八年级上学期期中考试英语作文(优质29篇)
校园生活丰富多彩,学习知识、参加活动、结交朋友,增强了团队合作精神,提升了个人能力,充实了每一天。下面是勤劳的小编为大家分享的八年级上学期期中考试英语作文范例,欢迎借鉴参考。
初二上册英语作文 篇1
Should students make friends on line ?some people say internet helps make many on line,students can more freely express their feelings and opinions,and even get help with their foreign language studies 。
However,Others think students should say making friends on line is a waste of time,which should be spent more meaningfully on ,some students get cheated on line 。
It is my opinion that students should place their study,health and safety before other for friendship,we can readily find it in our classmates and other people around us 。
8年级地理上册教学计划 篇2
一、指导思想
以《地理课程标准》为指导思想,以教导处工作计划为指导,加强课堂教学,高效地完成本学科教学目标。努力使每一位学生通过学习地理,能够对地理学知识有更深入的理解,能够对今后的学习方向有更多的思考;能够在探究能力、学习能力和解决问题能力方面有更多的发展;能够在责任感、合作精神和创新意识等方面得到提高。通过学习与学生生活密切联系的地理知识,传达地理思想,培养学生学习地理的兴趣和初步能力,最终培养学生“会学地理”。
二、学情分析
本学期,承担八年级六个教学班的地理教学任务,共计315名学生,每周12个课时。班级学生通过七年级地理教材的学习,学生对地理知识有了一定的感性认识,具备了初步的读图、分析、判断的能力。对世界概况有了一定的了解。对地理学习方法已基本掌握。但由于学生的程度参差不齐,在教学中要注重分层次,面向全体,不放弃每一位学生。
由于地理是小科,学生重视不够,这是一部分学生地理成绩提够不上来的重要原因。八年级下学期面临会考,从现在起必须做些工作,加强学生的重视,为地理会考取得好成绩打下基础。
三、教材分析
本册教科书的编写,以改变学生的学习方式为出发点,建立新的教材结构。提供丰富的学习素材和情境,使学生能够做到自主学习,养成终身学习的意识和能力。本册教科书始终如一地注意巩固和强化地理基本技能和能力,使学生在理解地理概念、分析和解释地理现象的过程中,获得基本技能和表达、交流等能力的训练。教科书结构设计中加大了“活动”的力度。力图加强地理教学中的学生活动,通过学生讨论、探究、实践的教学途径转变学生的学习方式。
第一章:从世界看中国,共分三节。主要学习中国的位置、疆域、行政区划、人口概况及其政策、民族的基本情况、我国的民族政策等。本章的教学难点是掌握三十四个省级行政区划的名称、简称和行政中心,以及部分省级行政区划的地理位置,记住中国省级行政区划图。
第二章:中国的自然环境,共分三节。介绍了我国地形、气候、河流、湖泊的基本情况,以及对我国经济发展的影响。本章在中国地理中占有重要的作用,内容繁多,难度较大。教学中应注意结合立体模型图,以帮助学生理解和掌握。
第三章:中国的自然资源,共分三节。介绍了我国主要自然资源的特点和分布。重点介绍了土地资源和水资源。指出了我国自然资源利用中存在的问题及其解决措施。
第四章:中国的经济发展,共分三节。介绍了中国的交通、农业和工业的基本情况,和取得的成就,分析影响交通、农业和工业分布的因素。
四、教学任务:
1、通过本期地理教学,使学生认识中国疆域概况,中国人口、民族特点及其地理分布特点,了解人口问题给社会、经济、资源、环境带来的压力。掌握三十四个省级行政区划的名称、简称和行政中心,记住中国省级行政区划图。
2、认识中国的自然环境,了解地形、地势,气候,河流概况,及其相互之间的联系与影响。并能分析对我国经济发展、人民生活的影响。
3、了解中国自然资源分布和自然资源所面临的现状,认识能源危机和环境问题给社会、经济发展造成的不良影响,提高学生节能、节约的主动意识。
4、认识我国经济发展的概况以及取得的成就。了解交通运输网络和工业、农业的地区分布差异,初步学会分析影响其分布的因素,学会合理地选择交通运输方式。
5、继续提高学生读图分析能力和空间想象能力,并能运用所学的地理知识解释生活中的一些地理现象。
6、通过八年级《地理》上册的课程学习,使学生真切的受到爱国主义教育,感受祖国的伟大和美好,树立可持续发展观的人地观。
五、完成本期教学任务的具体措施
1、必须以新理念指导教育教学。充分备课,吃透课标和教材,力求每节课,突出重点,突破难点,排除疑点。
2、关注学生个体差异。在面向全体的同时,进行分层次教学,做好转化后进生工作。
3、充分发挥教师的主导作用。进行学法指导,和探究性学习,提高学生思维能力。
4、突出地理学的“地域性”和“综合性”特征。引导学生从不同角度看待地理现象和问题,逐步形成对地理事物的“地域性”和“综合性”特征的认识。
5.密切联系生活和生产实际,注意挖掘学生的生活经历和体验,尽可能多地联系学生的生活实际,使学生感受到地理就在身旁,是鲜活的。
6、指导学生开展地理活动,培养学生动手能力和实践能力,寓德育与教学之中。
如何学好初中地理
1、初中地理学习,需要阅读、理解、记忆、掌握运用的知识较多,一定要提高学习效率。要找到最适合自己的学习方式:你可能更容易掌握条理化清晰的内容,杂乱的知识点一头雾水,那么你就需要学会梳理自己学过的知识点;你可能擅于听老师讲,自己看书效率低下,那么你一定要抓住上课有限的时间高效的掌握;你可能需要一边听一边勾勾画画写写,纯粹的听纯粹的看都不会让你注意力集中等等,找到自己学习上的一些特性,这样才能有效有针对性的解决。
2、学习掌握速读记忆的能力,提高学习复习效率。速读记忆是一种高效的“眼脑直映”式的学习、复习方法。速读记忆的练习参考《精英特全脑速读记忆训练软件》,用软件练习,每天一个多小时,一个月的时间,可以把阅读速度提高5、6倍,记忆力、理解力等也会得到相应的提高,最终提高学习、复习效率,取得好成绩。如果你的阅读、学习效率低的话,可以好好的去练习一下。
3、在学习之后要学会整合知识点。把需要学习的信息、掌握的知识分类,做成思维导图或知识点卡片,会让你的大脑、思维条理清醒,方便记忆、温习、掌握。同时,要学会把新知识和已学知识联系起来,不断糅合、完善你的知识体系。这样能够促进理解,加深记忆。
4、做题练习是少不了的,但不要一味的题海战术,把自己搞得一塌糊涂。做题的时候坚决独立完成、杜绝抄袭、杜绝题海战术。试题你是永远也做不完的,但题型是有限的,要学会反思、归类、整理出对应的解题思路。学习中还要学会阶段性的总结,了解自己最近的学习情况,进行调节和完善。
八年级上册英语作文 篇3
In China, our name is made up the first name and the last name. In America, people’s name is also made up of the first name and the last name, but there is something different. In China, our last names are from our ancestors, the last names are put in front of the first name. While in America, their last names are put behind the first name. The order is the main difference. After knowing the American name, we must be careful with these names, when we call the foreign friends, we should call their first name, when we are not familiar with them, we should call their last name. Don’t mix it with Chinese names.
八年级上册英语作文 篇4
1. 上课不能迟到。
2. 教室要保持(keep)干净和安静。
3. 见到老师要问好。(greet)
4. 不允许在教室里吃东西。
5. 不许在课堂上听音乐,玩游戏。
6. 不要损害花草树木。(pick flowers; climb trees)
School Rules
Welcome to our school, Mary. Here are some of our school rules. Let me tell you: We can't arrive late for class. We can't talk loudly in class. We have to be quiet in class, and we have to keep our class clean. When we meet the teachers on the way, we must greet them. We can't eat or drink in the classroom. But we can eat outside. We can't listen to music or play games in class, either. We can't pick flowers or climb trees.
英语八年级上册作文及翻译 篇5
How to Be Stronger 怎么变强壮
With the improvement of people’s material conditions, people have higher demands for living quality. People wish to be in good health and to have good living habits. How shall we do?
First, keep going to bed and getting up early every clay. Then do some exercises in the open air to breathe the fresh air in the morning, so we will have a pleasant mood in a day.
Then have balanced food to ensure our health. Eat more vegetables.
Being calm and good-natured is most important for our health. Hope you will be happy forever.
随着物质生活水平的提高,人们对生活质量有了更高的要求。人们希望拥有强壮的身体和良好的生活习惯。我们应怎样做? 第一,继续睡觉和起床早一粘土。然后做一些运动,在户外,呼吸清晨的新鲜空气,所以我们将在一天中都有一个愉快的心情。 然后有平衡的膳食来保证我们的健康。多吃蔬菜。 正在心平气和对我们的健康是最重要的。希望你永远快乐。
八年级上册英语作文 篇6
One day somebody sent Cao Cao an elephant.
Cao Cao wanted to know how heavy the elephant was,but there was nothing big enough to weigh it Chong told his father he could weigh the elephant if he had a big boat and a lot of heavy Cao and some other people were very surprised,but still he ordered his men to get everything they led the elephant down into the boat,the water came up,then Cao Chong marked the water they drove the elephant onto the bank and put the heavy stones in the boat until the water came up to the same last,Cao Chong told the men to weigh each of the this way,he weighed the elephant.
八年级上册英语作文 篇7
It is known to all that English is the international language. In China, English is the necessary subject for students to learn. A lot of students complain that it is so hard to master the foreign language.
While for me, I am the lucky guy, because I find my ways to learn it with fun. Listening to the songs and watching movies develops my interest. I want to see more about the world and learn about the culture, so only speaking English can bring me this chance. Whats more, I spend some time to write down some local saying when I watch movies. I practice it until I get familiar. Lets learn English withpassion.
八年级上册英语作文 篇8
Fathers Day is a celebration honoring fathers and celebrating fatherhood. Fathers Day was first born in 1910 in the United States.
It was proposed by a lady when she was celebrating Mothers Day. Many countries celebrate it on the third Sunday of June, but it is also celebrated widely on other days.
The celebrations are often related to gifts giving and family dinners. On Fathers Day, people choose specific flowers to respect for his father.
In China, because of the national character, few people wear flowers to show his respect for his father and there is no large celebrations.
But on the influence of the west, there are a growing number of people celebrate this holiday and tell their love to fathers.
北师大初中数学知识八年级上 篇9
第八章 数据的代表
-加权平均数:一组数据的权分加为,则称为这n个数的加权平均数。 (如:对某同学的数学、语文、科学三科的考查,成绩分别为72,50,88,而三项成绩的“权”分别为4、3、1,则加权平均数为:)
-一般地,n个数据按大小顺序排列,处于最中间位置的一个数据(或最中间两个数据的平均数)叫做这组数据的中位数。
-一组数据中出现次数最多的那个数据叫做这组数据的众数。
-众数着眼于对各数据出现次数的考察,中位数首先要将数据按大小顺序排列,而且要注意当数据个数为奇数时,中间的那个数据就是中位数;当数据个数为偶数时,居于中间的两个数据的平均数才是中位数,特别要注意一组数据的平均数和中位数是唯一的,但众数则不一定是唯一的。
八年级上册英语作文 篇10
I have many rules in my family.
On school days, I must get up at 6:00. I can’t play computer games. I can’t watch TV. I can’t go out and I can’t see my friends. I must do my homework. I have to go to bed at 10 weekends, I have to clean my room and wash my clothes. After dinner, I have to
do the dishes.
I never have fun every day.
初二上册英语作文 篇11
Now more and more people send cards to each other when in special days. most of us use paper cards,but now I want to introduce a special card to you, its the electronic card.
Electronic card is send in internet, it has a pecular function that can make animation and music during reading the card. it has a fast speed and has a variety of forms and when you want to choose one card. there are always several topics can give you s more,it can protect our environment and save the woods that make cards.
Use the eletronic card. I think it can give your amazing.
8年级上册英语重点 篇12
Module1 How to learn English
’s try to speak English as much as possible.尽可能多的
are going to talk about good ways to learn English. 我们将谈论一些学英语的好方法
talk to sb.对某人谈话 talk with 和。。。。交谈
not write down our mistakes in our notebook?
Why not do sth= why don’t you do sth.为什么不做。呢?只可跟动词原形
’s a good idea to spell and pronounce new words aloud every day.
It’s a good idea to do sth. 做。。。。。是个好主意
about listening to the radio?
How about doing sth=what about doing sth 做。怎么样?
films and listening to songs are great ways to learn English.
看电影和听歌是学英语的好方法
also advise you to talk about the films or songs with your friends.
我也建议你跟你的朋友谈论电影和歌曲
advise sb to do sth.建议某人做某事
advise doing sth建议做某事
am shy and I am afraid to speak to her.
be afraid to do sth害怕做某事或不敢做某事
be afraid of doing sth.担心会发生某事或某情况
a conversation开始谈话
’s natural to forget new words!
忘掉新单词是很合乎情理的
It’s +adj + for sb. to do sth.对
某人来说做某事。。。。。。
11.当million, billion, thousand等前有具体数词修饰时,他们不用加s,不加of。若表示不具体数目时则加s,加of
如果前面是several时,要么加s加of,要么不加s不加of
Several millions of years ago=several million years ago
Millions of people around the world visit them daily to improve their English.
Module2 My home town and my country
1.----How was your weekend?
-----Pretty good!相当好
用于对How’s........?或what do you think of.....?作答
2. In fact, it only became important in the 1980s. It’s getting bigger and busier.
1) in fact 表示“事实上”。
2) in the 1980s 表示“在20世纪80年代”。结构为“in the + 年 + s”。
in the 1930s 在20世纪30年
3) become important 表示“变得重要”。
getting bigger and cleaner 表示“变得更大和更干净”。
become 和 get 表示“变得”,用法等于 be。
’s on the coast near Hong Kong.
在海岸线上
day it will become as busy as Hong Kong.有一天它会变得跟香港一样繁忙
1)as + 形容词/副词 + as 和……一样
He is as tall as his brother.他和他的哥哥一样高。
2)not as + 形容词/副词 + as 不像……
This dictionary is not as useful as you think. 这本字典不如你想象的那样有用。
’s taller than many other buildings in Shenzhen.他比深圳一些其他的建筑物要高得多
many other+名词复数 一些其他的。。。。
many others 一些别人
’s the population of Shenzhen?深圳的人口是多少
The population of Shenzhen is larger than that of many other cities in China.
深圳的人口要比中国其他城市的人口要大得多。
Population 是一个集合名词,常与定冠词the连用,作主语时谓语动词用第三人称单数。例如:The world’s population is increasing faster and faster.
当主语是表示“人口的百分之几、几分之几”时,谓语动词用复数
About seventy percent of the population in China are farmers.
中国大约有百分之七十的人口是农民。
Shenzhen is larger in population than Beijing.
No, it isn’t. It’s smaller.
It is on the river Cam and has a population of about 120, a population of …表示“有……人口”。指人口的多少用large或small。
home town is especially(尤其) famous for it’s university.
be famous for因为。。。。而出名 be famous as 作为。。。。而出名
is best known for the White House.
be known for 因为。。。。而出名
be known as 作为。。。。。而出名
of tourists visit it every year to show respect to President Lincoln.
Show respect to对。。。。表示尊敬
10. There are lots of old buildings and churches to visit.
lots of 表示“许多,大量的”,后面加可数名词或不可数名词。例如:lots of buildings
11. England itself is part of an island,…
be part of 表示“是……的一部分”。
Taiwan is part of China.台湾是中国的一部分。
Module3 Nothing is more enjoyable than playing tennis.
popular with 受。。。的欢迎
’s the score? Score n.得分 v.得分、获胜、成功
’s the matter with you?你怎么了
What’s the trouble with 。。。。。?=what’s wrong with 。。。。。?
用来询问、谈论某人出了什么情况(看上去焦虑、难过或者生病)或者表示。。。。。出问题了
is not dangerous and it’s more relaxing too!
is more enjoyable than playing tennis.没有什么比打网球更令人高兴的了
mind. There’s still plenty of time for them to score.
Never mind 没有关系、不要紧、不要记在心上
Plenty of后跟可数名词和不可数名词都行
7、that means we have a better chance of winning.那意味着我们有更好的获胜的机会
have a chance of doing sth
have a chance to do sth
8、in the mornings and evenings, you can see people jogging in parks or along city streets.
See sb. doing sth看到某人正在做某事
See sb. do sth看到某人干了或经常干某事
Module4 planes, ships and trains
1. Maybe I should go to school by taxi.
交通工具英语搭配:By bus = take the bus
2、what about going by bike?
What about doing= how about doing ......;怎么样
3、the more information, the better.信息越多越好
The+比较级;the +比较级 越。。。。。越。。。。
Module 5 Lao She Teahouse
1、I wanted to see Beijing Opera, so Lingling offered to take me there.我想去看北京京剧,所以玲玲主动提出带我到那。want to do sth想做某事
2、it was difficult to understand the words. But the actors and actresses were excellent.
理解他们的话是很困难的,但是演员们很优秀
3、We only planned to watch for an hour, but in the end, we stayed for three hours.
4、LaoShe Teahouse gives a warm welcome to everyone from all over the world.
give sb. a..... Welcom对某人表示。。。欢迎
Module 6 Animals in danger
1、I am more interested to see the pandas in the Wolong Panda Reserve
我更感兴趣的是看到了卧龙熊猫保护区的熊猫
interested adj.感兴趣的 interesting adj.有趣的
Sb. be interested in.... 某人对某事感兴趣(主语必须是人)
Sth. be interesting.....某物令某人感兴趣(主语必须是物)
类似的单词有:
excited---exciting bored----boring moved---moving surprised---surprising
2、It allows people to get closer to them.它允许人们接近他们
allow sb. to do sth 允许某人做。。。 allow doing sth.允许做。。。。 allow that...承认。。。
They don’t allow smoking here.他们不允许在这吸烟
We had to allow that he was a good teacher.我们不得不承认他是一名好老师。
3、It’s sad to think of pandas and other animals in danger.
想起熊猫和其他动物正处于危险中是很悲伤地
in danger 处于危险中,有危险 out of danger脱离危险 dangerous adj有危险的
关于look的短语:
look after照顾照料= take care of look at 看 look into 调查
look up查阅、检查 look out小心、当心
look forward to doing sth. 期待做某事
4、we need to protect them better.我们需要更好地保护他们
1)need的用法:作实义动词,意为“需要” 当主语是人时,用need to do;当主语是物时,用need doing或need to be done
例如:we need to learn English.我们需要学英语
The trees need watering/ to be watered. 这些树需要浇水了
2)need作情态动词时,用于疑问句或否定句中。后面接动词原形,意为“需要、必须”
5、there is not enough land or forests, so the animals do not have a safe place to live.
enough+名词 形容词或副词+enough 如:old enough
6、let’s find out what else we can do to save as many animals as possible.
八年级上册英语作文 篇13
This holiday my sister and I went to Shanghai. My sister had just graduated and she wanted to find a job in Shanghai. My uncle lived in Shanghai, so we lived with him after we got there. On the first day we went to a lot of interesting places, including Waitan and Huangpu Park.
The next few days were spent helping my sister find a job. We read many advertisements in newspapers. My sister failed in getting the first job because they said she was too young. Then we lost our way and couldn’t find the second company. We had a map but the city is so big, so we had to asked someone for help and finally found the second company. The boss had a talk with my sister and asked her to wait at home for their decision. A month later we went home. My sister couldn’t find a job in Shanghai because she was not knowledgeable enough or she didn’t have enough experience.
In this holiday we learned that if we want to succeed in life, we have to work hard and get a lot of knowledge.
8年级上册英语作文 篇14
When talking about success, people will think about the successful career and a lot of fortune. It seems that owing the fame and the money can make a person perfect. We are easy to envy others for the things they have, as the saying that the food is delicious next door. But we must realize that sometimes we are envied by others. There is a story about two girls who live in the same room, one is believed to be the perfect student because she studies so well and the other have a lot of friends though she gets the ordinary score. When they communicate with each other, they find that they envy about each other. We should be proud of the things we have, such as our parents’ caring, it is incomparable. Cherishing what we have and we will be happy all the time.
在谈到成功时,人们会想到成功的事业和财富。似乎拥有名声和金钱可以使人完美。我们很容易嫉妒别人的东西,俗话说隔壁饭菜香。但我们必须意识到,有时我们会被别人羡慕。有一个故事关于两个住在同一个房间的女孩,其中一个被认为是一个完美的学生,因为她学习很好,另一个有很多朋友虽然她成绩一般。当她们相互交流时,发现彼此嫉妒。我们应该为自己拥有的东西而感到自豪,比如父母的关怀,它是无与伦比的。珍惜我们所拥有的,就会一直很幸福。
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八年级上册优秀英语作文 篇15
Fires often happen suddenly. What should we do to keep safe in a fire? Here is some advice.
First, we should keep calm and be brave. Second, call 119 for help and tell other people about the fire. Then leave the burning building as quickly as possible. But remember not to use the lift. Third, if there is smoke, cover our nose and mouth with a wet cloth. If our clothes are on fire, drop to the ground and roll(滚动). Finally, it is dangerous to go back into a burning building.
In short, follow what we learnt in school and we can be safe.
八年级上册英语作文 篇16
My Lifestyle
Let me tell you a little about my lifestyle.
I often eat fruit and vegetables. Apples and oranges are my favorites. I love junk food, too, and I eat it three or four times a week. I sleep less than seven hours ever day. I often feel sleepy. I brush my teeth once a day. I run in the morning, and play ping-pong after school. In my free time, I enjoy surfing the Internet. On weekends, I often go to the movies with my friends.
I think I’m kind of unhealthy. I shouldn’t eat too much junk food. I’ll try to have a balanced diet and sleep more. I should brush my teeth twice a day. I hope I can have a better lifestyle.
8年级上册物理课件 篇17
8年级上册物理课件
●教学目标
一、知识与能力
1.了解眼睛的构造,知道眼睛是怎样看见物体的。
2.了解眼镜是怎样矫正视力的。
二、过程与方法
1.通过观察实验和实践,培养学生理论联系实际,实事求是,求真务实的科学态度。
2.培养学生的观察能力、思维能力、参与组织能力和实践能力。
三、情感态度与价值观
1.通过活动,培养学生珍惜生命,关爱健康的意识,使其能自觉注意保护视力。
2.通过活动,培养学生将科学技术应用于日常生活的意识。
●教学重点新 课 标 第 一 网
培养学生用前面所学凸透镜成像规律的知识,加深对眼睛的了解。
●教学难点
将科学知识应用于日常生活的意识的培养。
●教学方法
观察法、讨论法。
●教学用具
挂图、眼睛模型、投影仪、球、书、石块、冰块、盐水杯。
●课时安排
1课时
●教学过程
一、创设情境、引入新课
[师]同学们闭上眼睛,用手摸这些东西(球、书、石块、冰块、盐水杯等),每摸一样,说出这是什么?
教师在教室里走动,拿着不同东西,让学生们摸。
[师]为什么不用眼睛,用手摸也能知道某一物体的形状、大小、凉热等特点?
[生]因为我们有触觉、味觉、视觉、嗅觉、听觉,能摸出来是触觉的作用。
[师]这位同学说得很对,其实这些东西的特点,除了用手摸,用眼睛一下就看出来了。眼睛是一个既复杂又奇妙的器官,它帮助我们认识身外的世界。判断物体的大小、距离、质感、颜色及长、宽等。你们知道眼睛是如何看到物体的吗?上节课我布置收集关于眼睛的资料,来说给大家听。
二、新课教学
[放投影片,课本图,眼球的结构,让同学们通过挂图和投影片讲叙]
[生甲]眼睛的主要部分是眼球,眼球近似球体。此外,还有一些附属结构。
[生乙]眼球由角膜、晶状体、瞳孔、虹膜、睫状体、玻璃体、视网膜等组成。
[生丙]晶状体和角膜的共同作用相当于一个凸透镜。
[生丁]外界物体反射来的光线,经过角膜、房水,由瞳孔进入眼球内部,再经过晶状体、玻璃体的折射作用,会聚在视网膜上,形成物体的像。
[生戊]视网膜上的视神经细胞受到光的刺激,把这个信号传输给大脑,我们就看到了物体。
[师]大家鼓掌,对他们精彩的讲解进行鼓励,谁还有不明的问题,请提出来。
[生甲]眼睛的睫毛、眼皮不属于眼球的构造,属于什么?
[生乙]眼睛睫状体起什么作用?
[生丙]眼睛中瞳孔起什么作用?
[生丁]视网膜起什么作用?
[生戊]既然晶状体和角膜的共同作用相当于一个凸透镜,那么物体能成什么样的像?
[师]请从你们收集到的资料中来解决这些问题。
[生甲]眼球的附属结构:有使眼球运动的肌肉,保护眼球的眼睑、睫毛、结膜、泪器。
[生乙]眼睛的睫状体的作用是调节晶状体的形状,当睫状体放松时,晶状体比较薄,远处物体射来的光刚好会聚在视网膜上,眼球可以看清远处的物体;当睫状体收缩时,晶状体变厚,对光的偏折能力变大,远处物体射来的光会聚在视网膜上,眼睛就可以看清近处的物体。
[生丙]眼睛瞳孔的作用能改变大小以控制进入眼睛的光线量,若在一个阳光普照的室外环境下,由于我们的眼睛不用太多光线来观看物体。瞳孔会自动收缩;相反,在漆黑的环境下,由于我们需要更多的光线来看物体,瞳孔便会自动扩张,瞳孔好像照相机的光圈。
[生丁]眼睛中视网膜的作用是把物体成的像的光能转变为神经冲动,再经过通往大脑的神经把神经冲动传入中枢神经系统,到达大脑皮层的视觉中枢,产生视觉,视网膜好像照相机的底片。
[生戊]光线由物体射入眼球,经过角膜和晶状体(相当于凸透镜)的折射,然后到达视网膜形成倒像,但我们看见的物体都是直立的物像,是因为受生活经验的影响。
[师]大家回答的非常好,说明在课下做了不少工作,说明准备得很充分,我们的眼睛就是这样:光线由我们所观看的物体发出,经过瞳孔(好像照相机的光圈)再由角膜及晶状体(功能好像照相机的镜头),再会聚在视网膜上(好像照相机的底片).
(一)眼睛(板书)
主要构造:
我们的眼睛实在了不起,我们不需要像摄影师那样,要考虑到环境的光暗或物体距离,我们的眼睛会自动作出调节,只要眼睛各部分运作正常,每一次我们均可“摄”取一张美丽动人的“相片”。
有些人单靠自身眼睛的调节已不能使像成在视网膜上,这种情况是怎么形成的,如何 处理?
[生甲]近视眼只能看清近处的物体,看不清远处的物体。
[生乙]远视眼只能看清远处的物体,看不清近处的物体。
[生丙]近视眼的视网膜距晶状体过远或者晶状体太凸,折光能力太强,致使远处射来的平行光线还未到达视网膜就已聚成一点,而当光线到达视网膜时又都分散开,形成一个模糊的光斑,因此看不清远处的物体。
[生丁]远视眼是视网膜距晶状体过近或者晶状体太扁,折光能力太弱,致使近处射来的平行光线到达视网膜时,还没有聚成一点,形成的物像落在视网膜的后方,在视网膜上形成一个模糊的光斑,因此,看不清近处的物体。
[师]那么怎么矫正近视眼和远视眼,看投影。(课本图、图)
[生甲]远视眼镜是凸透镜,是利用凸透镜能使光线会聚的特点,在眼睛前放一个凸透镜,就能使来自近处物体的光会聚在视网膜上。
[生乙]近视眼镜是凹透镜,使入射的平行光线经过凹透镜发散后再射入眼睛。
[师]同学们回答的非常好,还有什么问题?请继续提问。
[生甲]近视眼是怎么形成的?
[生乙]老花眼是怎么形成的?
[生丙]怎么预防近视眼?
[生丁]眼镜的度数是怎么来的?
[生戊]什么是假性近视?什么是真性近视?
[师]请同学们根据搜集的资料,找出答案。
[生甲]形成近视眼的原因,一般认为主要有两个方面,一是遗传因素,二是环境因素。其中环境因素是形成学生近视眼的主要因素。
[生乙]儿童、青少年眼睛中的晶状体弹性强,睫状体的调节能力大,但是如果看书写字的姿势不正确,书本放得离眼太近,或采光、照明条件不好,或持续用眼的时间过长,都会使睫状体内的肌肉持续收缩。晶状体凸度增大,久而久之,一旦看远方物体时,睫状体内的肌肉就不能放松。变凸的晶状体也不能恢复到正常状态,这样就造成了假性近视。
[生丁]发生假性近视以后,如仍不注意采取有效的防治措施,就会造成变凸的晶状体不能恢复正常,就会变成真性近视。
[生戊]预防近视要做到:①读书、写字姿势要正确,眼与书的距离约33 cm.②看书一小时后休息,要远眺几分钟。③要认真做眼睛保健操。④不要在直射强光下看书。⑤不在光暗的地方看书。⑥不躺卧着看书。⑦不在走路时看书。
[生己]老花眼产生的原因是由于老年人的晶状体弹性变差,调节能力减弱的缘故。是生理性变化引起的,看远物不需要晶状体的调节,但在看近物时,需要配戴凸透镜。
[生庚]透镜焦距f的长短标志着折光本领的大小。焦距越短,折光本领越大,通常把透镜焦距的倒数叫做透镜焦度。用Φ表示。
如果远视很严重,所戴花镜(凸透镜)的折光本领应该大一些,透镜焦度就要大一些,平时说的眼镜片的度数,就是镜片的透镜焦度乘100的值。例如:100度远视镜片的透镜焦度是1 m-1,它的焦距是1 m.
凸透镜(远视镜片)的度数是正数,凹透镜(近视镜片)的度数是负数。
[师]现在我们知道了近视眼是怎么形成的了,但如何预防?如何矫正?
(二)近视眼及其矫正。
近视眼的视网膜距晶状体过远,从无穷远处射来的平行光线会聚在视网膜前,用凹透镜矫正。
(三)远视眼及其矫正。
远视眼的视网膜距晶状体过近,平行光的会聚点在视网膜后,用凸透镜矫正。
三、小结
1.眼睛好像一架照相机,主要由瞳孔(好像照相机的光圈)、角膜及晶体(功能好像照相机的镜头)、视网膜(好像照相机的底片)组成。
2.近视眼用凹透镜矫正。
3.远视眼用凸透镜矫正。
四、布置作业
P64动手动脑学物理①②③.
P65科学世界①②.
[动手动脑学物理习题参考答案]
1.甲图平行光线通过凸透镜后,会聚于焦点,是正确的。
过焦点的光通过凸透镜后应成为平行光,而乙图的光线向外发散,是错误的。
光线通过凹透镜后应发散,而丙图的光线通过凹透镜后向主光轴�
丁图的光线通过凹透镜后发散,是错误的。
2.近视镜片中间薄、边缘厚,是凹透镜;远视镜片中间厚、边缘薄,是凸透镜。度数深的眼镜镜面弯曲得较多,度数浅的眼睛镜片相对较平。
3.让学生们各自测出自己眼睛的近点并且相互比较,正常眼、近视眼、远视眼的近点是不同的。近视眼的明视距离相对正常眼要短,而远视眼的明视距离相对正常眼要长。
4.+300度是远视镜片,-200度是近视镜片。焦度是3 m-1,焦距是3 m,眼镜度数越深,说明眼镜镜片焦距越短。
五、板书设计
近视眼:凹透镜
远视眼:凸透镜
教学反思:
第五节 显微镜和望远镜
●教学目标
一、知识与能力
了解显微镜和望远镜的基本结构。
二、过程与方法
1.通过观察引导学生发散思维。
2.培养学生综合运用所学知识的能力。
三、情感态度与价值观
初步认识科学技术对于社会发展和人类生活的影响。
●教学重点
知道显微镜和望远镜的基本结构。
●教学难点
利用两组凸透镜成像规律理解显微镜和望远镜的原理。
●教学用具
投影仪、投影片、显微镜、望远镜、放大镜、挂图、火柴盒、无色透明塑料膜、水、烧杯、滴管、装片(植物).
●课时安排
1课时
●教学过程
一、创设情景,引入新课
[师]我们在白纸上画一个小箭头,用两个火柴盒压住,在它上面放一块无色透明的塑料膜,用滴管从烧杯中吸上一些水,小心地把一个小水滴滴在塑料膜上,观察到什么现象?
[教师巡回指导,让学生们调整水滴跟桌面的距离,或滴管改变水滴的直径]
[生甲]观察到一个正立、放大的箭头。
[生乙]观察到一个倒立、放大的箭头。
[生丙]从实验中可得出小水滴相当于一个凸透镜。
[生丁]改变水滴跟桌面的距离可得到正立放大的箭头和倒立放大的箭头。
[师]同学们回答的很好,说明大家观察很认真,那么如何能放大的更大?
学生们再一次调整或借用其他仪器尝试。
[生甲]从水滴看到一个和原来方向相反放大的箭头。再用一只放大镜来观察水滴。当放大镜移到一定位置,看到一个清晰的和原来方向相反的被放得很大的箭头。
[学生们对这个结果很迷惘]
[师]看投影,在胶片上我画了个很小很小的三角形,经过投影仪,在屏幕上成倒立、放大的像,现在通过放大镜,再看看。
[生甲]看到比原来三角形大好几倍的三角形。
[学生们走出困惑,情绪高涨]
[师]人眼观察物体的细微结构时,分辨本领是有限的。把物体移近些,可以看得清楚些,借用放大镜可以看得更清楚些,但对于太细微的结构,如生物的细胞,移得再近,用放大镜也是看不清楚的。我们从实验中可看出用两个凸透镜可以放得更大。利用这个原理就制成了显微镜,想了解它吗?想了解什么?
二、新课教学
[生甲]显微镜的构造?
[生乙]显微镜的原理是什么?
[生丙]如何使用显微镜?
结合课本图投影。让学生讲解。
[生甲]显微镜镜筒的两端各有一组透镜,每组透镜的作用都相当于一个凸透镜。
[生乙]靠近眼睛的凸透镜叫做目镜。
[生丙]靠近被观察物体的凸透镜叫做物镜。
[生丁]反光镜可旋转,能使反射光线从下方照射到被观察的物体上,增大物体的亮度。
[生戊]载物台用来放置被观察的物体,载物台中央有一圆孔,反射镜反射的光线从下方穿过圆孔,照射在被观察物体上。
[生己]物体通过物镜成放大的实像。这个实像作为目镜的“物体”,通过目镜成放大的虚像。
[生庚]显微镜使物体经过两次放大,使肉眼看不到的小物体能看到。
[生辛]物镜使物体成放大、实像,物距在二倍焦距和焦距之间;目镜使物体成放大、虚像,物距在焦距之内。
[师]同学们回答的很好,显微镜就是根据这个原理制成的。显微镜的放大倍数等于物镜的放大倍数乘以目镜的放大倍数。
一、显微镜(板书)
原理:物镜 f<u<2f
目镜 u<f
[师]现在我们使用显微镜观察装片,先用眼观察,再用显微镜观察。
[学生们观察、教师指导,使学生观察到清晰的像]
[师]约4前在荷兰的一个小镇上,一个磨眼镜片的手艺人不经意地透过一前一后放置的两个镜片去看远处的景物时,发现这些景物近了许多,大约16,意大利的科学家伽利略知道了这件事,他在研究之后,用两个凸透镜做成了一台望远镜。他后来不断改进,用自己的望远镜第一次发现了天上的银河并不是一片连续发光的云,而是由许多的星星组成的。他发现月亮表面并不是平坦的。而是有许多高低不同的环形山;发现了太阳黑子,看到了土星周围有一圈光环。更重要的是,他发现了有四颗卫星绕着木星转,很神奇是吗?想了 解吧。
[生甲]望远镜的构造是什么样的?
[生乙]为什么使用望远镜观察物体会感到物体被放大?
[生丙]望远镜和显微镜的原理是一样的吗?
[生丁]望远镜的种类有哪些?
[师]看投影课本图,仔细观察分析的结论。
[生甲]望远镜也是由两组凸透镜组成。
[生乙]靠近眼睛的叫做目镜,靠近被观测物体的叫做物镜。
[生丙]物镜的作用是使远处的物体在焦点附近成实像。
[生丁]目镜的作用相当于一个放大镜,用来把这个像放大。
[生戊]我们能看清一个物体,它对我们的眼睛所成“视角”的大小十分重要,物体对眼睛所成视角的大小和物体本身大小有关,还和物体到眼睛的距离有关。
[生己]望远镜的物镜所成的像虽然比原来的物体小,但它离我们的眼睛很近,再加上目镜的放大作用。视角就可以变得很大。
[生庚]显微镜和望远镜都是由两组凸透镜组成,都叫物镜和目镜,但有不同的地方,显微镜的物镜,物距在二倍焦距和一倍焦距之间,成倒立放大的像。作用是使物体进行一次放大。望远镜的物镜,物距在二倍焦距以外,成倒立缩小的像,作用是把远处的物体与眼睛的距离拉近。目镜都起放大镜的作用。
[师]就同学们所讲,望远镜的物镜直径比我们眼睛的瞳孔大得多,这样它可以会聚更多的光使得所成的像更加明亮。这一点在观测天空中的暗星时非常重要。现代天文望远镜都是力求把物镜口径加大,以求观测到更暗的星。
二、望远镜(板书)
原理:物像:u>2f 倒立 缩小的像。
目镜:u<f 正立、放大的像。
[生甲]望远镜有伽利略望远镜、开普勒望远镜、牛顿式反射望远镜、哈勃太空望远镜。
[生乙]还有普通望远镜、军事望远镜、红外线望远镜。
[师]大家知道的真多,能否简单介绍一下。
[生甲]我们见到的普通望远镜和军事望远镜都是双tong的,是双tong望远镜,它的两个镜筒都是拐了弯的。在拐弯处分别安装了两个“全反射棱镜”。这种设计一方面缩短了镜筒的长度,再者经过那两块棱镜的两次反射也能使本来倒立的像正立过来。
[生乙]望远镜观看的对象在远处,无法移近,要看清楚就要尽可能多地收集远处物体发来的光,观察宇宙中的星体时更是要这样。因此望远镜的物镜总是做得尽可能大,用玻璃不可能制成直径很大的透镜。因为大块玻璃质地不均匀,会导致透镜折光不好,使看到的像有扭曲,为了消除凸透镜成像的缺点,牛顿发明了反射望远镜。它的物镜不用凸透镜而用凹面反射镜,也使光在目镜焦点处成实像。
[生丙]在地面上用望远镜观察星空时,星体发来的光在穿过大气层的时候,要被吸收一些,还要受到不规则折射的影响,因此大大影响像的质量,为改进对星体的观察,1990年美国向太空发射了一台望远镜,叫哈勃太空望远镜。
三、小结
引导学生小结
显微镜构造:
①物镜 原理 f<u<2f
②目镜 原理 放大镜作用
望远镜构造:
①物镜 原理 u>2f
②目镜 原理 放大镜作用
四、布置作业
P67动手动脑学物理①②.
[动手动脑学物理参考答案]
1.注意这个实验可以让学生做一下,但要注意安全,不要让烧热的玻璃珠碰到身体。
2.把放大倍数较大(焦距较短)的凸透镜放在靠近眼睛的位置时,远处物体看上去变大了;两个放大镜位置对调以后,远处物体看上去变小了。为了使远处的物体看得更清楚,就要使物体放大,所以要用两个焦距不同的放大镜。如果两个放大镜焦距相同,就没有放大作用了。
五、板书设计
复习课 复习和应用
●教学目标
一、知识与能力
1.了解凸透镜和凹透镜。
2.了解生活中的透镜、照相机、投影仪、放大镜、显微镜和望远镜。
二、过程与方法
1.通过对实物和挂图的观察,培养学生观察能力。
2.通过探索凸透镜成像规律,培养学生研究,探索新问题的能力。
3.通过眼睛、眼镜、显微镜、望远镜的教学培养学生应用物理知识解决实际问题的能力。
4.通过本章知识体系的概括,提高学生整理综合能力。
三、情感态度与价值观
1.通过对照相机、投影仪、显微镜、望远镜的学习,培养学生欣赏人物美、自然美的能力,更加热爱祖国,立志为科学献身。
2.通过介绍我国古代在光学方面的研究成果,进行爱国主义教育。
●教学重点
凸透镜成像规律及其应用。
●教学难点
凸透镜的应用。
●教学方法
归纳法、讲练、结合法。
●教学用具
投影仪、投影片。
●课时安排
1课时
●教学过程
一、知识整理
学生思考,讨论问题(投影片)并回答:
①什么叫凸透镜?什么叫凹透镜?
②什么叫焦点?什么叫焦距?
③凸透镜、凹透镜对光线各起什么作用?
④凸透镜的成像规律是怎样的?
⑤照相机的构造及原理?
⑥投影仪的构造及原理?
⑦放大镜的原理?
⑧眼睛的成像原理?
⑨显微镜的光学原理?
⑩望远镜的光学原理?
二、知识网络(板书)
第六章 质量与密度
第一节 质 量
●教学目标
1.知识与技能
通过分子和原子的概念初步理解“物质的量”的含义。
初步认识质量的概念,知道质量的单位。
了解天平的构造,掌握天平的使用方法。
2.过程与方法
体验一些物体的质量,对一些常见物体的质量有估测的能力。
通过用天平测量常见的固体和液体的质量,掌握天平的使用方法。
通过观察、实验,认识质量是不随物体的形状、状态、空间位置而变的物理量。
3.情感态度与价值观
通过天平使用的技能训练,培养学生严谨的科学态度与协作精神。
通过对物质质量的测量,获得成功的喜悦。
●教学重点与难点
重点:质量的单位和用天平测质量。
难点:正确使用天平测量固体和液体的质量。
教学方法:演示法
教学用具:课件,器材
教学课时:1课时
教学过程:
引入新课
问:自行车是用哪些材料制成?
答:钢、铁、橡胶等材料制成的,教师接着说明:一般我们把自行车称为物体,钢、铁、橡胶等称为物质。这样我们可以说:自行车这个物体是由钢、铁、橡胶等物质构成的,其它物体如:铁钉、铁锤、桌子、凳子等也都是由物质构成的。
新课教学
1. 质量
(1)对实物的观察,引入质量的概念
铁钉和铁锤含有铁这种物质的多少不同,桌子和凳子含有木这种物质我多少不同,物理学里为了表示这性质就引入的质量这个物理量。
质量是表示物体所含物质的多少。用符号:“m”表示。
(2)举例说明物体的质量不随它的形状、状态、位置和温度而改变。
2. 质量的单位
(1) 国际单位:千克(kg)
(2) 其他单位:吨(t);克(g);毫克(mg)。
(3) 进率:1吨=1000千克;1千克=1000克;1克=1000毫克。
看P103表中一些物体的质量。
3.质量的测量--天平
(1) 介绍常用测质量的器具:案称;杆称;台称;电子称;天平
(2) 托盘天平的构造及使用方法
构造:底座;横梁;托盘;平衡螺母;指针;分度盘;游码;标尺
(3) 天平的使用
天平的调节:把天平放在水平台上,把游码放在标尺左端的零刻线处;调节横平衡螺母,使指针指在分度盘的中线处,这时横梁平衡。
A. 把被测物体放在左盘,用镊子向右盘里加减砝码并调节游码在标尺上的位置,直到横梁恢复平衡。
B. 这时盘中砝码的总质量加上游码在标尺上所对和刻度值,就等于被测物体的质量。
教师强调:1、调节平衡螺累母按:指针左偏就向右调;右偏向左调。
2、天平调节平衡后,左右盘不能对调,平衡螺母不能再动。
3、取砝码时一定要用镊子。
4、往盘里加砝码应先估计被测物的质量,再从大到小加砝
码,当加到最小一个砝码时太重了,则应改用移游码。
5、游码的读数是读游码的左边所对标尺的刻度值。
(4) 天平使用注意事项:
A.不能超过称量(天平的称量=所配砝码总质量+游砝最大读数)。
B.取砝码要用镊子,并轻拿轻放。
C.保持天平干燥、清洁。
小 结:
板书设计:
第二节 质量
一、质量
1.什么叫质量:物体所含物质的多少叫质量
2.单位:国际单位:千克(kg)
其他单位:吨(t);克(g);毫克(mg)
进率:1000进
二、质量测量
1.实验室测量质量工具:天平
2.天平的使用
(1) 把天平放在水平台上,把游码放在标尺左端的零刻线处;
(2) 调节横平衡螺母,使指针指在分度盘的中线处,这时横梁平衡。
(3) 物体放在左盘,砝码放在右盘,并调节游码,直到横梁恢复平衡。
(4) 物体质量=砝码总质量+游码读数
三。使用天平注意事项:P103:1;2
教学反思:
第二节 密度
●教学目标
1.知识与技能
知道质量的初步概念及其单位。
通过实际操作,掌握天平的使用方法。
用分子和原子的概念初步理解“物质的量”的含义。学会测量固体和液
体的质量。
2.过程与方法
通过观察、实验,认识质量是不随物体的形状、状态、空间位置而变化的物理量。
3.情感态度与价值观
通过天平使用的技能训练,培养学生严谨的科学态度与协作精神。
●教学重点与难点
重点:质量的单位;天平的使用。
难点:认识质量是物体的属性。
●教学课时:1时
●教学过程:
引入新课
自然界是由各种各样的物质组成,不同物质有不同的特性,我们正是根据物质的这些特性来区分、鉴别不同的物质。特性指物质本身具有的,能进行相互区别、辩认的一种性质,例如颜色、气味、味道、硬度等都是物质的特性,这节课我们来学生物质的另一种特性--密度
新课教学
1. 建立密度的概念
(1)实验:用天平测出木块和石块的质量;用刻度尺和量筒、水测出木块和石块的体积。数据如下:
质量(克) 体积(厘米3) 质量/体积 (克/厘米3)
木块1 5 10
木块2 10 20
石块1 10 4
石块2 20 8
(2)分析数据
A. 木块的体积增大几倍,它的质量也增大几倍,质量和体积比值一定
B. 石块的体积增大几倍,它的质量也增大几倍,质量和体积比值一定
C. 木块的质量跟体积比值不等于石块的质量跟体积的比值。
从表演中可看出不同种类的物质,质量跟体积的比值是不同的,质量跟体积的比值就等于单位体积的质量,可见单位体积的质量反映了物质的一种特性,密度就是表示这种特性的物理量。
(3)建立概念
A.密度定义:某种物质单位体积的质量叫做这种物质的密度,符号ρ
B.密度公式:ρ=m/V;m 表示质量,V表示体积
C.密度单位:千克/米3(kg/m3);克/厘米3(g/cm3)
1g/cm3=1000kg/m3=103kg/m3
(4)例题:一铁块质量是吨,体积是米3,铁块密度多大?
已知:m==×103kg;V=
求:ρ
解:
答:铁块的密度是×103kg/m3
2.密度物理意义
水的密度是×103kg/m3表示1米3水的质量是×103千克。
3.思考与讨论
(1)对同种类物质,密度ρ与质量m和V的关系。
(2)不同种类物质,密度是否相同?这说明什么?
(3)公式 的物理意义。
4.巩固练习:《学物理》
小 结:
板书设计:
第三节 密度
1. 密度的定义:某种物质单位体积的质量叫这种物质的密度,用符号:“ρ”表示
2. 密度公式:
3. 密度单位:千克/米3(kg/m3)
克/厘米3(g/cm3)
1g/cm3=1000kg/m3=103kg/m3
4. 密度物理意义:ρ水=×103kg/m3表示1米3水的质量是×103千克。
密度是物质的一种特性,它只与物质的种类有关,与它的质量和体积无关,(因为同种物质的质量与体积的比值一定)。
教学反思:
第三节 测量物质的密度
●教学目标
1.知识与技能
通过实验进一步巩固物质密度的概念;进一步熟悉天平构造及其使用;
学会用量筒测量液体、不规则形状物体体积的方法。
2.过程与方法
通过探究活动学会测量液体和固体的密度。
对利用物理公式间接测定物理量这种科学方法有感性认识。
通过探究过程的体验,使学生对测量性探究方法,从实验原理、实验器材的选取和使用、实验步骤的设计、数据的采集与处理到得出结果,分析实验误差有初步认识和感受。
3.情感态度与价值观
通过实验数据记录、处理的体验,使学生养成实事求是、严谨的科学态度。
通过探究活动中的交流与合作体验,使学生认识交流与合作的重要性,培养主动与他人合作的精神。敢于提出与别人不同的见解,也勇于放弃或修正自己的错误观念。
●教学重点与难点
学会用天平和量筒测固体和液体密度的原理和方法。
使学生通过实验能对密度的物理意义加深理解。
教学课时:1时
教学过程:
引入新课
1.复习:什么是物质的密度?计算密度的公式是什么?要求出物质的密度要知道哪些量?
2.出示小石块和1杯盐水,指出用天平可以称出石块与盐水的质量,但刻度尺却无法测出它的体积。本实验我们学习用量筒。
新课教学
1.引导学生看课本实验的“目的”,对照实验的器材将桌面上的用具对照检查。
2.讲述量筒(或量杯)的使用方法。
介绍量筒和量杯,mL是体积单位“毫升”的符号,1mL=1cm3。
学生观察量筒的量程和最小刻度值。
学生观察图7-6、图7-7量筒或量杯使用时怎样放?怎样读出液体和体积?看样测固体的体积?
教师引导学生讨论得出:
(1)测量时量筒或量杯使用时应放平稳
(2)读数时社,视线要与筒内或杯内液体液面相平,(如:测水的体积,由于水面是凹形的,读数时,视线要跟凹面相平;如测水银的体积,由于水银面是凸形的,读数时视线要凸面平。)
(3)测固体体积的方法:
①在量筒内倒适量的水(以浸没待测固体为准)读出体积V1;
②用细线栓好固体慢慢放入到量筒内,读出此时水和待测固体的
总体积V2
③用V2-V1,得到侍测因体的体积。
1. 学生分组实验:测石块的密度
提问:测石块的密度合理的实验步骤是什么?
教师强调:这了减小实验误差,应该先用天平称出石块的质量。
学生实验操作。
2. 学生分组实验:测盐水的密度
提问:测盐水的密度的步骤是什么?
教师指出:(1)本实验测盐水的质量的方法与第二节测液体质量的方法不一样。 (2)为了计算方法,盐水的体积应尽量取整数。
学生实验操作。
把两组学生的实验数据填入黑板的表格内。分析数据是否合理。
3. 讨论课本:想想议议
小 结:
板书设计:
第四节 测量物质的密度
1.目的:用天平和量筒测固体和液体的密度
2.原理:据密度公式:
3.器材:天平和砝码,量筒,烧杯(2个)石块,细线,水,盐水。
4.步骤:参书本
教学反思:
第四节 密度与社会生活
●教学目的
1.知道密度知识的应用。
2.知道物质的密度还与温度有关
3.培养学生分析问题和解决问题的能力。
●教学重点和难点
运用密度知识鉴别物质和解决实际问题。
●教学用具
4千克的铅球、水桶、体重计、纸风车、酒精灯、细线、圆底烧瓶、水槽。
●教学过程
(一)复习提问
1.已知铁的密度为×103千克/米3,它的。物理意义是什么?
2.铅的密度为×103千克/米3,与铁的密度不同,这说明了什么问题?
(二)引入新课
密度是物质的基本属性,每种物质都有自己的密度。密度在我们的社会生活中有重要的价值。在解决不同的实际问题时,密度知识是如何应用的。
1.密度与物质鉴别
讨论的问题如下:
教师出示学生体育课上用的4kg的铅球,问学生:你如何判断,这种铅球是否用铅制成的?请说出你的办法来。
学生分组讨论:
学生作答:先分别测量出铅球的质量和体积,再利用密度公式求出它的密度,判断它是否是铅组成的。
又提问:如何利用家里能找到的器材,测出测量出铅球的质量和体积呢?
用体重计测出铅球的质量,可以用水桶做排水器材测出铅球排开水的质量,即可算出铅球的体积。
实验:
计算:
总结:用密度鉴别物质问题,如果我们计算出某一物体密度和密度表中某一物质密度相同,我们只能说可能是这种物质,如果前边例题中你不知道是铜球,这样用计算出的密度值
一分析就会错误地认为是铁球。而且从密度表中可以看到花岗石的密度在 之间,如果一块花岗石密度恰好是 ,我们能说它是铝吗?显然不能。所以在用密度进行物质鉴别时往往还要配合利用物质的其他特性,比如颜色、硬度等等。更科学的鉴别物质的方法,应采用化学分析或光谱分析,鉴别组成它的化学元素成分。
同种物质的密度一般是不变的,如一瓶水用去一半,剩下一半水的质量是原来的二分之一,但密度不变。
问题:同种物质的密度一定不变吗?如果某物体的质量不变,而它的体积改变了呢?
实验:气体的热胀冷缩实验
介绍实验装置:圆底烧瓶上用带有注有一小段红墨水的玻璃管的橡皮塞密闭空气。先后放入热水和冷水中,观察。
现象:烧瓶放在热水中时,里面的红墨水向外移动,说明瓶内气体受热体积膨胀了。
而放在冷水中时,里面的红墨水向里移动,说明瓶内气体遇冷体积收缩了。
同学们回家可做类似实验:两个吹胀的气球分别放在冰箱的冷藏室和炉火附近。观察现象。
上面的实验说明最物质的密度与温度有关。
2.密度与温度
自然现象中风的形成也是因为密度与温度有关形成的
做风形成的实验:教材P22
空气因受热体积膨胀,密度变小而上升,热空气上升后,温度低的冷空气就从四面八方流过来从而形成了风。
思考:教材P24
根据气体的密度随温度变化而变化的现象,试分析房间里的暖气一般都安装在窗户下面的道理。
暖气周围的空气受热体积膨胀,密度变小而上升,靠近窗户的冷空气密度大,下沉到暖气周围,又受热上升,利用这种冷热空气的对流,可以使整个屋子暖和起来。
人们很早就利用风力了,例如:利用风力来取水,灌溉、磨面,推动帆船、滑翔机等,近代大规模应用风力,主要在发电上。
温度可以改变物质的密度。固体、液体的热胀冷缩不像气体那样明显,因而密度受温度的影响比较小。
设问:难道所有的物质都有热胀冷缩的性质吗?
水的凝固点是0℃,北方的寒冷冬天,气温在0℃以下,湖面结成了冰,行人可以在湖面上行走。湖底还有鱼存活吗?
300多年前,人类就已知道水在4摄氏度时密度最大这一现象。在冰湖中作的测试表明,表面冻结的湖里,冰面以下的水体中密度从上至下递增(这是当然的事了,重在下,轻在上),温度也是由上至下递增,从表层水体的0℃至底层水体的4℃。正是因为这个特性,湖里的鱼类能够在严寒的冬天躲在底层水体中,不至于被冻成冰块。
水在0-4℃之间,是热缩冷胀,在4℃以上是热胀冷缩。
水的反膨胀现象,给人们带来了好处,江河湖面的水结冰时,因为冰的体积膨胀,密度比水小,总是浮在水面上;而水到了4℃,密度最大,总是沉在下面。这样,冰块就成了一层天然的防寒屏障,使江河湖海不至于一冻到底,使大量的水下生物得以生存。
水的反常膨胀,给人类生活也带来不方便。北方的冬天,放在户外的自来水管将冻裂。所以对自来水管的保护显得尤其重要。
观看密度在社会生活中的其它应用的影片。
教学反思:
复习课 质量与密度复习
一、质量
1.质量
定义:物体所今物质的多少叫做这种物质的质量。
单位:kg,g,mg,t
2.质量的测量
工具:天平,秤(磅秤,台秤等)
方法:(用天平的测量质量的方法)
3.质量的特性
质量是物体的属性,它不随物体的形状、状态、位置发生变化而变化。
二、密度
1.同种物质的质量与体积的关系
同种物质的质量和体积具有正比例关系。
2.密度
①定义:单位体积的某种物质的质量叫做这种物质的密度。
密度公式:ρ=m/V
ρ------密度------千克每立方米(kg/m3)
m-----质量------千克(kg)
V------体积------立方米(m3)
②密度的单位:千克每立方米,符号是kg/m3。像这种单位叫做组合单位 。
有时密度的单位也用克每立方厘米,符号是g/m3。
1g/cm3=1×103kg/m3
3.一些物质的密度值(常温常压下)
①不同的物质,密度一般不同;同一种物质在不同状态下的密度也不相同。
如水在不同的状态下,密度不同。
②物质密度与温度、压强有关;
③密度相同的不一定是同一种物质,如冰、蜡、植物油密度都 是×103kg/m3;还有煤油、酒精密度都是×103kg/m3;
④金属固体的密度较大。
⑤水的密度值:×103kg/m3,表示体积1立方米的水,质量是×103kg。
读作:水的密度是×103千克每立方米。
4.密度的应用
密度的应用:利用公式ρ=m/V变形可得到m=ρV和V=m/ρ,即在知道物质的密度和体积时,可以计算出物质的质量;在知道物质的质量和密度时,可以计算出物质的体积。
三、测量物质的密度
1.测量原理:ρ=m/V
2.量筒的使用
①认识量筒:单位,量程,分度值。
②读数方法:读数时,视线应与刻度面垂直,与液面相平。如果量筒中液面是凹形的,与凹面相平,如果液面是凸形的,与凸面相平。
③液体的体积可以利用量筒直接测量。
④用量筒测量固体的体积:等量占据空间替代法。
a. “溢杯法”测量固体的体积。
b.先测出量筒中适量水的体积,再测出量筒内水和完全浸没于水中的固体的总体积V2,两者相减,就得到固体的体积V= V2 - V1。
3.测量固体的密度(石块):
[注意]要先测石块的质量,再测石块的体积。
4.测量液体的密度(盐水):用剩余法测体积
5.测量不规则的塑料的密度(其密度比水小):悬垂法和针压法测体积。
八年级英语上册第一单元试卷及答案 篇18
一、单项选择
1. —Have you read today’s newspaper?
—No, I haven’t. Is there_____in it?
A. something important B. anything special
C. new anything
2. —Believe in_____, Jack! I’m sure you can make it.
—Thank you, Mum.
A. myself B. yourself C. himself D. herself
3. —Who helped you clean the bedroom yesterday, Kitty?
—_____. I cleaned it all by myself.
A. Nobody B. Everybody
C. Somebody D. Anybody
4. The Greens arrived_____New York_____a sunny day.
A. in; in B. at; in C. at; on D. in; on
5. Oh, the food smells good. But what does it_____like?
A. seem B. sound C. taste D. feel
6. —What a nice watch! When_____you_____it?
—Three days ago.
A. do; buy B. did; bought
C. were; buy D. did; buy
7. —Is your friend Michael still in Australia?
—I don’t know. I have_____information about him because we haven’t seen each other for_____years.
A. a little; a few B. little; a few
C. a few; a little D. few; a little
8. The Great Wall is_____famous_____lots of visitors all over the world come to visit it every year.
A. so; that B. such; that
C. enough; that D. very; that
9. Jane_____to Mount Tai with her family last summer vacation.
A. go B. goes
C. went D. is going
10. —I’m going to spend my summer holiday in Hawaii.
—What a lucky boy!_____And don’t forget to send me a postcard.
A. That sounds good. B. Have a good time!
C. Good luck! D. Can I go with you?
二、完形填空
This week, I asked my classmates about their vacations. Here are some of their answers.
Linda 1 to Sydney, Australia. The 2 was sunny and the people 3 friendly to her. She went there by 4 and the air trip was relaxing. She went to Sydney Opera House. It’s wonderful. She had a 5 vacation.
Alice went 6 her aunt. At first the weather was 7 and wet, she had to stay at the house. She watched TV 8 the TV shows were boring. Later on the weather got better. So she went shopping with her aunt. The shop assistants were all 9 and kind. She bought something nice for herself.
Peter stayed at home. First he did his homework. It was a little difficult. Then he 10 computer games. They were interesting. He thought his vacation was OK.
1. A. go_____ B. goes_____ C. went_____ D. going
2. A. place B. weather C. museum D. beach
3. A. were B. was C. is D. are
4. A. bike B. train C. bus D. plane
5. A. bad B. terrible C. great D. boring
6. A. to visit B. visiting C. visited D. visits
7. A. sunny B. rainy C. windy D. wind
8. A. but B. and C. or D. with
9. A. friend B. impolite C. unfriendly D. friendly
10. A. play B. played C. listened D. wrote
三、阅读理解
Our family went to the Yellow Stone National Park last summer vacation. Our son, Tom, wanted to see bears there. And what an experience(经历)it was!
When we got there, we put up our tent and went to explore(探险). As we returned, we heard our daughter Susie cry out. And then we saw a bear go into our camp.
Tom wanted his father to chase(追赶)him away. His father said, “No. It’s dangerous to chase a bear. And don’t let him chase you. ”Susie said, “What shall we do? Maybe we should climb a tree. ”Tom said, “No. We have to get him out of there. He might go to sleep in our tent. ”“Maybe we could make him leave if we put some honey outside for him to eat. ”Susie suggested. Then I said, “How are you going to get the honey? It’s in the tent. ”We watched the bear go into the tent and heard him upset(翻倒; 弄翻)everything inside. “It’s foolish for us to try to chase him away. ”said my husband, “Leave him alone and wait for him to come out. ”We waited, but the bear stayed inside. We had to sleep in the car that night.
1. Tom wanted to go to Yellow Stone National Park to see_____.
A. tigers B. wolves C. bears D. birds
2. Where did the family go on vacation last summer?
A. They went to the Central Park.
B. They went to Yellow Stone National Park.
C. They went to a zoo.
D. They just stayed at home.
3. Who do you think saw the bear first?
A. Susie. B. Tom. C. The writer. D. The writer’s husband.
4. What did they do when they saw a bear go into their tent?
A. They chased the bear away.
B. They stayed outside the tent and did nothing.
C. They climbed up a tree.
D. They put some honey outside for the bear to eat.
5. What did the bear do in the tent?
A. He ate the honey.
B. He chased the people away.
C. He drank the beer.
D. He turned things upside down.
四、根据句意及首字母或汉语提示完成单词。
1. H_____ can lay eggs, but cocks can’t.
2. He got wet in the rain because he didn’t have an u_____ .
3. You can ask_____ (任何人)here for help if you are in trouble.
4. Most people_____ (不喜欢)selfish men.
5. Both of John’s parents are_____ (商人). They’re very busy.
五、用所给动词的适当形式填空, 完成短文。
I 1 (go)to Paris with my parents on vacation. The weather was fine. We 2 (have)a sightseeing(观光)tour of the city and we also 3 (visit)some of the famous places like the Eiffel Tower. From Paris we traveled down to the south of France near Marseilles by boat. We 4 (stay)there for three days. There we had a lot of fun. We 5 (swim)in the sea and 6 (take)many photos. We also 7 (do)lots of sports on the beach. We 8 (go)back a week later by train. The people there 9 (be)friendly. The food 10 (be)delicious. So the trip was really great.
1. __________2. __________3.
4. __________5. __________6.
7. __________8. __________9.
10.
六、书面表达
北京(Beijing)是中国的首都(capital)。它有许多名胜古迹(interesting places), 如长城、故宫、天安门广场等。假如你是Kate, 你到北京旅游, 度过了一个愉快的暑假。请你给你的同学Mike发一封电子邮件, 介绍一下北京之旅。
要求: 1. 语言正确, 条理清晰, 书写规范;
2. 词数: 60~80个词。
Dear Mike,
________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Yours,
Kate
8年级上册第一单元英语作文 篇19
My first day in college was frustrating at first while pleasantly surprising at the end.
The new campus was quite different from what I dreamed of. Actually it was as big as my high school. Besides instead of huge buildings, there were only some small ones. Although it took me some time to make my decision, I finally made up my mind not to beat a retreat. After all, you couldn’t judge a book by its cover, as an old idem told us, so did my college. And what happened next proved that I chose a wise choice.
On entering the dormitory, I met 10 smiling faces that greeted me warmly, which made me pretty amazed and delighted. It was a great honor for me to be arranged to live with 10 freshmen who came from 9 different provinces. We liked each other at first sight. Sharing our experiences and talking without any embarrassment, we felt like long last friends.
Visiting came in the afternoon when the college leaders and teachers came to our dormitory to give us worm welcome. Whenever we need help, someone always came to lend us a hand. I never felt myself a new comer, but a member of the big family.
That life was not all roses was what I learned on my first day in college. I realized that difficulties in life couldn’t be avoided, but that if one didn’t run away but met unexpected hardship, one mastered all obstacles and at the came out victorious.
8年级上册政治知识点 篇20
第二课 我与父母交朋友
1.产生烦恼的原因:(或两代人产生隔阂的原因)
①小时候,我们对父母依附、崇拜。进入青春期后,我们有了自己的思想,开始独立行事,渴望从家长那里拿到“解放证书”,渴望父母像对待大人那样对待我们,甚至挑战父母的权威。我们与父母之间产生了矛盾。
②父母对我们的关爱没变,只是要求更加严格,免不了多叮嘱几句,在我们听不进时,就觉得家长唠叨、啰嗦。于是,我们与父母之间就产生了矛盾。
③我们与父母的人生经历、生活经验、社会地位不同,对社会规范的熟悉程度也不同,在生活态度、价值观念、兴趣爱好、行为方式等方式难免产生较大差异。
2.逆反心理有危害
(1)逆反心理产生的表现
具体表现为:要我这样、我偏要那样;你说这个好,我非说那个好;让我相信这个,我非相信那个不可。
(2)辨证看待逆反心理 P21、P22
⑶逆反心理的危害
在多数情况下,逆反心理导致的与父母的对抗,其结果都是既惩罚了自己又伤害了父母。
3.架起理解的桥梁(怎样与父母沟通?)
(1)在家中,父母与子女之间容易产生矛盾积极的做法是从现实中架起理解的桥梁。我们做子女的,要走进父母,亲近父母、努力化解矛盾,与父母携手同行。
(2)程序:冷静—商量—找出分歧----解决方法 (P24正文前三句)
(3)我们与父母进行沟通,彼此了解是前提,尊重理解是关键。理解父母的有效方法是换位思考,沟通结果要求同存异。
(4)与父母交往的艺术:
①赞赏父母,赞赏中增进亲情。
②认真聆听,聆听中获得教益。
③帮助父母,用行动感动亲人。
④在家庭交往中,与父母不必太计较。即使父母错了,也要多原谅,不要非与父母争个高低上下。
八年级上册英语作文 篇21
Li Xiaohu spent too much time playing computer games and he fell behind others. As a good/close friend of his, I must do something to help him.
First, I think it's very important for him to learn lessons well. He should spend most of his time on his study instead of computer games.
Secondly, I must tell him that playing computer games too much is bad for his health, especially for his eyes. So he must give it up. I can play more sports with him after school. Maybe he will become more interested in sports than computer games. And then I'll ask him to concentrate more on his study. Of course, I will try my best to help him with all his subjects. I think I can do it in many fun ways and let him find much fun in studying. At the same time, I'll ask both his parents and our teachers to help him, too. If I try these, I'm sure he will make great progress soon.
八年级上册优秀英语作文 篇22
This holiday my sister and I went to Shanghai. My sister had just graduated and she wanted to find a job in Shanghai. My uncle lived in Shanghai, so we lived with him after we got there. On the first day we went to a lot of interesting places, including Waitan and Huangpu Park.
The next few days were spent helping my sister find a job. We read many advertisements in newspapers. My sister failed in getting the first job because they said she was too young. Then we lost our way and couldn’t find the second company. We had a map but the city is so big, so we had to asked someone for help and finally found the second company. The boss had a talk with my sister and asked her to wait at home for their decision. A month later we went home. My sister couldn’t find a job in Shanghai because she was not knowledgeable enough or she didn’t have enough experience.
In this holiday we learned that if we want to succeed in life, we have to work hard and get a lot of knowledge.(约185字)
八年级上册英语作文 篇23
I get up at seven o’clock in the morning every day. After I brush my teeth and wash face, I eat my breakfast. My mother makes the breakfast for me. I go to school at 7:30am, and come back from school at 6 pm. Before I go to bed I will do some homework. I usually go to sleep at 10 pm. On the weekend, I will go to play football with my friends, in the summer we like to go swimming. These are my daily life.
我每天早上7点起床。刷牙洗脸之后我就吃早餐,早餐是我妈妈做的。我7:30去学校,下午6点放学。在我上床睡觉之前我会做一些作业。我平时是10点睡觉。周末的时候,我会跟朋友去踢足球,夏天时去游泳。这些就是我的日常生活。
八年级上册英语作文 篇24
Should students make friends on line ?some people say internet helps make many on line,students can more freely express their feelings and opinions,and even get help with their foreign language studies .
However,Others think students should say making friends on line is a waste of time,which should be spent more meaningfully on students get cheated on line .
It is my opinion that students should place their study,health and safety before other for friendship,we can readily find it in our classmates and other people around us .
八年级上册英语作文 篇25
Li Xiaohu spent too much time playing computer games and he fell behind others. As a good/close friend of his, I must do something to help him.
First, I think its very important for him to learn lessons well. He should spend most of his time on his study instead of computer games.
Secondly, I must tell him that playing computer games too much is bad for his health, especially for his eyes. So he must give it up. I can play more sports with him after school. Maybe he will become more interested in sports than computer games. And then Ill ask him to concentrate more on his study. Of course, I will try my best to help him with all his subjects. I think I can do it in many fun ways and let him find much fun in studying. At the same time, Ill ask both his parents and our teachers to help him, too. If I try these, Im sure he will make great progress soon.
语文八年级上册第一单元试卷 篇26
第二课 网络生活空间
(一)网络改变世界
1.网络是怎样改变世界的?
(1)网络丰富日常生活(2)网络推动社会进步
2.网络怎样丰富日常生活?
(1)网络让我们日常生活中的信息传递和交流变得方便迅捷;
(2)互联网打破了传统人际交往的时空限制,促进了人际交往;
(3)网络让我们的生活变得更加便利和丰富多彩。
3.网络怎样推动社会进步?
(1)网� 促进了人财物的流动,推动了传统产业转型升级,提升了经济发展生平;
(2)网络促进了民主政治的进步。互联网丰富了民主形式、拓宽了民主渠道,有利于保障公民的知情权、参与权、表达权、监督权。
(3)网� 互联网提高了文化传播的速度,促进了创新资源的合作与共享。
4.网络中的陷阱(弊端)有哪些?
(1)网络信息良莠不齐。信息变得丰富的同时,也出现了一些虚假的、不良的信息;
(2)沉迷于网络,影响学习、工作和生活;
(3)个人隐私容易被侵犯。
(二) 合理利用网络
1.怎样理性参与网络生活?
(1)我们要提高媒介素养,积极利用互联网获取新知、促进沟通、完善自我。
(2)我们要注意浏览、寻找与学习和工作有关的信息,不应该在无关信息面前停留,不应该在无聊信息上浪费精力,更不可沉溺于网络,要学会“信息节食”。
(3)我们要学会辨析网络信息,让谣言止于智者,自觉抵制暴力、色情、恐怖等不良信息。
(4)恪守道德、遵守法律。做一名负责的网络参与者。
2.网络生活基本准则是什么?
恪守道德、遵守法律。
3.怎样传播网络正能量?
(1)充分利用网络平台为社会发展建言献策。可以向有关部门积极提出意见和建议,为决策科学化、民主化贡献力量。
(2)我们要在网上传播正能量。共同培育积极健康、向上向善的网络文化,让网络公共空间充满正能量,高扬主旋律。
初一政治有效学习方法
1、注意认真听讲,积极回答、勤于思考、勇于提出问题。
教师备课是将知识和学生的实际结合起来的,具有很强的针对性。
同学们应当认真听讲,积极回答并认真倾听别人回答的问题,思考老师的点评和你的思考有什么不同,以便加深理解所学内容。
还要勇于提出问题,首先是要发现问题,而发现问题是思考问题的关键。
再如有的同学通过人类社会发展一般过程的学习提出苏联解体、东欧巨变如何看待,就是一个很有质量的问题。
2、高质量地完成作业。
政治题的练习要少而精。
要把每次练习当做考试,按考试要求去做,做后要总结:错在哪,为什么,如何改进等等,每次练习都要有提高。
3、掌握知识的脉络要点。
①以生产力和生产关系的矛盾运动来串起整个人类社会发展的大动脉。
②以总复习上的课题、节题、框题、标题为线索。
③以各课的知识体系表为依据。
④最好是在此基础上自己总结知识体系表,化为自己的知识,做到知识的理论化、系统化,做到纲举目张、胸有成竹。
4、分专题、多角度练习。
新目标八年级英语上册第一单元知识点总结 篇27
九年级上册英语第一单元
I.重点词汇
Test----exam words----vocabulary
Excited----exciting amazing----surprising
sometimes----sometime----some times----some time
for example----such as----like begin with----to begin with
maybe----perhaps----probably affect----influence
problem----question
II.重点词组
…for… skills
…about… …at all
excited about up
mistakes of all
begin with on
afraid of at
sentences notes
down sure
with up
up about
angry with by
other a problem
…as… about
…into… one’s best
the help of …to…
about off
III.重点句子
learn by studying with a group.
’s too hard to understand the voices.
finds watching movies frustrating because the people speak too quickly.
get excited about something and then end up speaking in Chinese.
don’t you join an English club to practice English.
year my English class was difficult for me.
was easy for me to understand the teacher.
I’m enjoying learning English.
we have seen young children playing together.
IV.话题语法
1.谈论学习方法
+v-ing结构做状语
九年级英语第一单元语法知识点
Unit1 Section A
: ①通过…..方式(途径)。后跟名词,代词,或者动名词。He won the game by a lot of practice. 他通过大量的练习赢得比赛。Tom understand the meaning of the word by looking it up in the dictionary . T om 通过查字典明白了这个单词的含义。
对by提问用how,
---How do you study for a test? ---By listening to tapes.你是怎样为考试而学习的?通过听磁带。
②在…..旁边。例:by the window/the door
③乘坐交通工具 例:by bus/car
④在……之前,到……为止。例:by October在10月前 ⑤被 例:English is spoken by many people. by 还可以表示:“在…旁”、“靠近”、
2. 如:The students often talk about movie after class. 学生们常常在课后讨论电影。
3.提建议的句子: ①What/ how about +doing sth.? 如:What/ How about going shopping? ②Why don’t you + do sth.? 如:Why don’t you go shopping? ③Why
not + do sth. ? 如:Why not go shopping?
④Let’s + do sth. 如: Let’s go shopping ⑤Shall we/ I + do sth.? 如:Shall we/ I go shopping?
多。a lot 许多,很,非常,在句子中做程度状语,修饰动词,也可修饰形容词副词的比较级, I t rains a lot at this time of year. :I eat a lot. 我吃了许多。that way ,前面省略了in 用那种方式
的话。
too…to 太…而不能 常用的句型 too+adj./adv. + to do sth. 如:I’m too tired to say anything. 我太累了,什么都不想说。 6.学生有更独特的见解。
specific 形容词特有的,特别的,具体的,明确的,
Our English teacher has a specific teaching style. 我们的英语老师有独特的教学风格。
Suggestion名词,建议,意见动词是suggest Can you make a suggestion for me?你能给我提个建议吗? 7.助。
下课文里的新单词。
Ming feels differently .李明的感觉不同。
副词,不同地,有区别地 现看电影是令人沮丧的,因为他们说话太快。
find watching movies frustrating 发现看电影令人沮丧 find + 宾语 + (名词 形容词 等) I find him friendly. 我发现他很友好。 I found him working in the garden.我发现他真在花园工作。
We found him in bed. He found the window closed. aloud 大声朗读
的用法,三个词都与”大声“或”响亮“有关。 ①aloud是副词,重点在出声能让人听见,但声音不一定很大, 常用在读书或说话上。通常放在动词之后。aloud没有比较级 形式。如: He read the story aloud to his son.他朗读那篇故事给他儿子听。 ②loud可作形容词或副词。用作副词时,常与speak, talk, laugh等动词连用,多用于比
较级,须放在动词之后。如: She told us to speak a little louder. 她让我们说大声一点。 ③loudly是副词,与loud同义,有时两者可替换使用,但往往 含有令人讨厌或打扰别人的意思,可位于动词之前或之后。如: He does not talk loudly or laugh loudly in public. 他不当众大声谈笑。
都没有。 not …at all 一点也不 根本不 如:I like milk very much. I don’t like coffee at all. 我非常喜欢牛奶。我一点也不喜欢咖啡。 not经常可以和助动词结合在一起,at all 则放在句尾
还是说中文。.get excited 高兴,激动
be / get excited about sth.=== be / get excited about doing sth. === be excited to do sth. 对…感兴奋 如:I am / get excited about going to Beijing.=== I am excited to go to Beijing. 我对去北京感到兴奋。 .
常见的有: ①是:am 、is、are ②保持:keep、stay
③ 转变:become、get、turn ④ ……起来 feel、look、smell、taste、sound后面都接形容词
① end up doing sth 终止做某事,结束做某事 如:The party ended up singing. 晚会以唱歌而结束。 ② end up with sth. 以。。。结束 如: The party ended up with her singing. 晚会以她的歌唱而告终。end up 结束
Section B and self check 单词我不会读。
pronounce 动词,发音。
I can pronounce all the words in the newspaper我能读出这张报纸上所有的单词。
I don’t know how to pronounce this new word我不知道这个生词怎么发音。
.pronunciation 名词 发音,发音方法
He has a good pronunciation. 他的发音很好。
The word has two pronunciations.这个单词有两个发音。 2不懂口语。
spoken 口头的,口语的。 speaking 讲话的,说某种语言的。
make mistakes 犯错make mistakes in sth. 在某方面犯错 by mistake 错误地,无意地
I often make mistakes. 我经常犯错
The more careful you are,the fewer mistakes you will make.你越细心,你 犯的错误就越少。
He made a lot of mistakes in his spelling.他在拼写方面犯了很多错误。
I took your book by mistake.我错拿了你的书。 ..right使。。。正确get +sb\sth+adj. 使某人或某物处于某种状态The work gets me tied.
get + 宾语 + 宾补(形容词 ) 使某种情况发生
Get the shoes clean. 把鞋擦干净 Get Mr. Green to come. 让格林先生进来
You can’t get him waiting. 你不能让他老等着
5.一起练习(英语)的伙伴。 动词不定式做定语 He is always the first to come.他总是第一个到的人。 I have nothing to say. 我没什么可说。
I need a pen to write with.我需要写字的钢笔。
I need some paper to write on. 我需要一些写字的纸 I don’t have a room to live in.我没有住的房间。 6.
先,当老师讲话时对我来说明白她说的什么是不容易的。 first of all 首先 。强调顺序。 We will learn Lesson 4,first of read new words.. 7.个词都能听懂。
begin with 以。。。作为开始=start with
To start with,we don’t have enough money.起初,我们没有足够的钱。
8.词是没关系的。
later on 随后,以后
It will be hotter later on随后天气会更加炎热。 He became a scientist later on.
realize 动词,认识到,了解到
I realized I made a mistakes.我意识到我犯了一个错误。 We did n’t realize the serious problem.我们没有意识到这个严重的问题。
讲话,�
afraid 动词,怕,害怕
be afraid of sb/sth, 害怕某人、某物
be afraid to do sth.=be afraid of doing sth.害怕做某事 be afraid that恐怕,担心,表示委婉语气
Don’t be afraid of making mistakes when you speak English.说英语时不要害怕出错。
The little girl is afraid of the dark.这个下女孩怕黑。
She is afraid to go out alone at night.她害怕晚上独自出门。 I am afraid that I have to go now.我恐怕要走了。 laugh at sb. 笑话;取笑(某人)
Don’t laugh at people in trouble.不要嘲笑陷入困境中的人。
We are busy taking notes carefully in class.上课的时候我没忙着认真做笔记。
Mr Zhang was taking notes while listening to the talk.张先生边听报告边做笔记。 14.的老师留下了深刻的印象。
impress 动词,使感动,使。。。留下深刻印象
be impressed by ...因。。。而印象深刻
We are impressed by her smile.我们对她的微笑印象深刻。
My progress in English has impressed my classmates greatly.我在英语上取得的进步给同学们留下深刻的印象。
17. make up 组成、构成
18. one of +(the+ 形容词比较级)+名词复数形式 …其中之一 如: She is one of the most popular teachers. 她是欢迎的教师之一。
22. unless 假如不,除非 引导条件状语从句 如:You will fail unless you work hard..假如你不努力你会失败。 I won’t write unless he writes first. 除非他先写要不我不写
23. deal with 处理 如:I dealt with a lot of problem.
24. worry about sb./ sth. 担心某人/ 某事 如:Mother worried about his son just now. 妈妈刚才担心他的儿子。
25. be angry with sb. 对某人生气 如:I was angry with her. 我对她生气。
) 过去 如: Two years went by句末 ①放在定句末表示“也” ②两者中的“任一”
③either…or… 或者…或者。…引导主语部分,谓语动词按照就近原则处理
完成,是个较正式的词,后不能接 finish指日常事物的完成
,an 与连用表示“又一”,“再一”。
例:Please give me a second apple. There comes a fifth girl.
除非,如果不,等于“if not”本身就表示否定,引导条件状语从句,主句为将来时,条件状语从句用一般现在时表示将来。
例:My baby sister doesn’t cry unless she’s hungry. =My baby sister doesn’t cry if she isn’t hungry.
Unless you take more care, you’ll have an accident.如果你不多加小心的话,你会出事的。
:adv 代替,更换。
例:We have no coffee, would you like tea instead? 我们没有咖啡了,改喝茶好吗?
Stuart was ill, so I went instead. 斯图尔病了,所以换了我去。
instead of 作为某人或某事物的替换
例:Let’s play cards instead of watching TV.
Give me the red one instead of the green one.
英语第一单元上册重点句子及句型
Unit 1
1. They go as fast as they can.
as…as sb. (one) can = as …as possible 尽可能地……
as…as中间加原级的形容词或副词。例:
I will work as hard as I can. 我将尽可能努力工作。
He ran as fast as he could. 他拼命地跑。
Please come here as soon as you can. 请尽快来这里。
2. We call the first Olympic Games the ”ancient“ Olympics.
我们把早期的运动会叫做”古代“奥运会。
call sb. / sth. +n. 称呼某人/某物……,后面的名词作宾语补足语。
例:We call the boy DaMao. 我们称呼那个男孩大毛。
类似于这种可以用名词或名词短语作宾语补足语的动词有:
name/call/make/choose/find/think等。例:
We chose him our monitor at yesterday's class meeting.
昨天班会我们选他当我们的班长。
I find him a clever boy. 我觉得他是个聪明的孩子。
3. It seemed that Zhuang Yong and Jenny Thompson, an American swimmer, had finished at the same time.
看上去好像庄泳和美国游泳选手詹尼·汤姆森同时游完全程。
以下几种方式可以表示”看起来……,似乎……“
It seems that +从句
seem to be +adj.
seem +adj.
例:Danny seemed excited. (Danny seemed to be excited.)
丹尼似乎很激动。
seem to do sth.
例:When his wife's pet cat died, Alan didn't seem to care at all.
艾伦妻子的宠猫死了,他好象一点也不在乎。
4. Diving is one of the most popular events at the Olympics.
潜水是奥运会欢迎的项目之一。
one of… ……其中之一,后常加级及名词复数。例:
Changjiang is one of the longest rivers in the world.
长江是世界最长的河流之一。
5. Make your country proud. 使你的国家因你而自豪。
proud作宾语补足语,修饰宾语your country;
make的用法:
make the bed 铺床 make tea 沏茶
make dumplings 包饺子 make a car 制造汽车
be made of 由……制成
make sb. /sth. +n. 使某人/某物成为……
made sb. /sth. +adj. 使某人/某物如何……
make sb. /sth. do 使某人/某物做某事
名词/形容词/do (不定式,省to),作宾语补足语。
6. …his team came in twentieth. 他的队第二十名。
twentieth 第二十
整十数的序数词,变y为ie加th。例:
ninety→ninetieth fifty→fiftieth
7. We had such an interesting day at school today.
我们今天在学校度过了这么有趣的一天。
这句话也可以说成:We had so interesting a day at school today.
such和so意思都是”如此……/这样……",但用法不同。
It is so interesting a film that we all want to see it once more.
它是如此有趣的电影,我们都想再看一遍。
Thanks a lot for sending me such beautiful pictures by e-mail!
多谢你用e-mail给我发来这么漂亮的图片。
He is so weak that he can't work on.
他如此虚弱以致不能再继续工作。
8. If I don't. I won't be able to sleep tonight.
如果我不写下来的话,我今晚睡不着觉。
此句是if构成的条件状语从句,要用一般现在时代替将来时。
I'll go to the park with my friends if it doesn't rain tomorrow.
如果明天不下雨,我要和朋友去公园。
9. If he practises walking on pizzas, he'll do better next time.
如果他保持练习在比萨饼上走的话,下次他会表现好一些。
finish, enjoy, practise, keep, mind后常加动名词作宾语。例:
You'd better practise speaking English both in and after class.
你在课上课下练习说英语。
8年级英语邀请函 篇28
MR glue BB/CC, poplar core, Thickness tolerance +/-, M/C is below bb%, flat surface
If you don’t try you will never know our quality level .you will increase your competitor‘s absolute advantage, they have our good quality and better prices, how can you compete with them
We really want to establish long-lasting business relationship with you, so we give you these best prices .you can compare with other suppliers now .you can ask your people to test the ’t miss this great opportunity .if you want to try, please tell me ASAP, because the prices will be higher USDb to 1b after September bbb I think your current vendors are small factories ,right so they have lower prices with lower quality .I think they have not stable and fixed quality .if they have better orders they will not do your orders .I am looking forward to hearing from your reply. bbb please make your decision ASAP. If you want to strengthen your competitive power, please don’t hesitate to ask me send the sales contract to you.
初二上册英语作文 篇29
Today, as the development of technology, people can change their faces by doing plastic surgery, because of the commercial ads, people are highly effected by the exaggerated facts that they can be the shining stars. So people pay special attention on the outlooks, they want to look perfect, as far as I am concerned, the true beauty is nothing with perfect looking, only the inner beauty makes you shining.
In the fairly tale of Cinderella, the prince chooses the poor girl instead of the beautiful girls, because he admires Cinderella’s inner beauty, though she is nobody. Though it is just a story, it tells people that inner beauty makes one outstanding. People can make their faces perfect, but there is no way to fulfill their inner beauty by technology. Inner beauty is the most precious thing, beautiful outlook will fade away with the time, but inner beauty won’t, it only getting valuable.
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