查看原文
其他

仁爱版英语九年级上册Unit 2 Topic 3 知识点+单元测试(含听力)

更多微课点关注→ 绿色学习平台 2023-02-12

获取配套课件教案习题试卷请拉到文末

Unit 2 Topic 3What can we do at home to protect the environment.

知识点汇总

【重点短语】1.environmental protection 环境保护2.work for 为……而工作3.both sides of paper 纸的两面4.plastic bags 塑料袋5.encourage sb. to do sth. 鼓励某人做某事6.ought to do sth.应该做某事7.shut off 关闭8.instead of + n./pron./v-ing代替,而不是9.after all 毕竟,归根结底10.renewable energy 可再生能源11.in people’s everyday/daily lives在人们的日常生活中12.require sb. to do sth. 要求某人做某事      be required to do sth. 被要求做某事13.in the near future 在不久的将来14.reach a top speed of… 达到最高时速……15.run out 用完,耗尽16.remove…from… 把……从……除去17.hurry up 赶快,快点18.give up 放弃19.though/although/even though even if 虽然,尽管.引导让步状语从句,不能和but连用,但可与yet,still 连用。【词形转换】1.protect v.保护    protection n.保护,防卫2.agree v.同意    agreement n.同意,一致,协议    disagreement n.分歧,争论3.electric adj.用电的,电动的                  n.带电体,电动车辆    electricity n.电,电能4.cloth n.织物,布料    clothes n.衣服5.German n.德国人,德语                 adj.德国的,德国人的,德语的    Germany n.德国6.dry adj.干燥的,雨少的,干性的           v.使……干,弄干,擦干    drier n.烘干机,吹风机    drily adv.干燥地7.plant v.种植    planter n.种植园主8.marry v.嫁,娶,结婚    married adj.已婚的,有配偶的9.weigh v.称……重量    weight n.重量,分量10.history n.历史     historical adj.历史的11.different adj.不同的      difference n.[C]差别,差异【重点句型】1.Recycling can protect the environment, and it can save money, too.回收可以保护环境并且可以节约钱。2.Some things we have done are good for the earth while some are bad.我们所做的一些事情对地球有益然而一些有害。3.--Would you like to be a greener person?  --Of course, I’d love to.  --你愿意成为一个环保使者吗?  --当然,我很乐意。4.we should use both sides of paper and reuse plastic bags.我们应该使用纸的两面并且重新利用塑料袋。5.You ought to shut off the electricity when you leave a room.当你离开房间的时候,你应该关掉电。6.You’d better walk or ride a bike instead of taking a bus or a taxi if you travel a short distance.如果短距离旅行,你最好步行或骑自行车而不是乘公共汽车或出租车。7.Easier said than done.说起来容易,做起来难。8.Actions speak louder than words.事实胜于雄辩。
【话题写作】

加拿大著名专家(expert) Jim Greenlaw将于本周日来我校作演讲,演讲主题是 Saving Our Earth,假如你是校学生会主席,请写则通知,告诉全校同学。

时间: 上午9: 00

地点: 学校礼堂

要求: 带好笔记本并做好笔记;保持会场安静,不要乱扔垃圾。(5分)


【参考范文】

Boys and girls,

    An expert called Jim Greenlaw from Canada will come to our school this Sunday. He will give a report on“Saving Our Earth”. The report will start/begin in our school hall at 9: 00 in the morning. Remember to bring your notebooks. Please keep quiet and don’t throw rubbish about.

    That’s all. Thank you.


点击预习:仁爱版英语九年级上册教材/电子课本


单元测试卷(含听力)

仁爱版初中英语九年级上册Unit2 Topic3 单元测试

(满分100分,时间90分钟)

题号


第一部分

第二部分

第三部分

总分


得分












第一部分  听力 (20分)

Ⅰ.听句子,根据所听句子的内容和所提的问题,选择符合题意的图画回答问题。每个句子读一遍。(5分)

(   )1.What is the boy doing?

     

A                B               C

(   )2.What does the girl want to do?

     

A                B               C

(   )3.What does the woman think make her fell uncomfortable?

     

A                B               C

(   )4.What caused the bad weather according to the man?

     

A                B               C

(   )5.What is used for producing electricity in Ann’s hometown?

     

A                B               C


Ⅱ.听对话,选择正确答案。每段对话读两遍。(5分)

(   )6.What does Jenny do to help protect the environment?

A.She reuses plastic bottles.

B.She reuses paper cups.

C.She reuses plastic bags.

(   )7.What’s the article about?

A.Pollution.     B.Population.   C.Invention.

(   )8.What’s the book about?

        A.Saving electricity.        

        B.Protecting the environment.        

        C.Saving material.

(   )9.Is Jane a greener person?

A.We don’t know.         

B.Of course she is.         

C.No, she isn’t.

(   )10.What does the man advise the woman to do?

     A.To give him some work to protect the environment.     B.To give him some advice about protecting the environment.     C.To help spread the message about protecting the environment.

Ⅲ.听短文,选择正确答案。短文读两遍。(5分)

(   )11.Scientists want to change_____into field land.

      A.desert     B.forest    C.sea

(   )12. _____land is becoming desert.

      A.Less and less  B.More and more   C.Fewer and fewer

(   )13. _____prevent the wind from blowing the dirt away.

      A.Rain      B.Desert       C.Plants

(   )14.Scientist_____change the desert in a short time.

      A.can’t    B.may      C.ought to

(   )15.Scientists think people_____bad things to the earth.

      A.did      B.will do   C.are doing


Ⅳ.听短文,选择最佳答案。短文读两遍。(5分)

(   )16.What’s the date today?

      A.April 2nd.    B.April 22nd.       C.May 22nd.

(   )17.What did they go to the park to do?

      A.Do some cleaning.         B.Enjoying themselves.    

     C.Planting trees.

(   )18.What did they do near the lake and in the woods?

      A.They played games.    B.They put up some notices.

      C.They collected rubbish.

(   )19.What did they tell the visitors?

      A.The danger of pollution.        

      B.The importance of planting trees.

      C.The importance of protecting the environment.

(   )20.How did they feel after they went home?

      A.Tired and hungry.         B.Tired but happy.        

     C.Sad and angry.


第二部分 基础知识运用(55分)

Ⅰ.单项选择。(10分)

(   )1.—When _____ he leave for the city?

—He _____ next week.

A.does, will leave        B.does, leaves        

C.has, has left            D.will, leaves

(   )2.—It’s a long story, but you can hardly find new words in it.

—Good! _____ it will be too hard for children.

A.So                B.And           

 C.But                D.Or

(   )3.—What _____I to say to him?

—Tell him to save water.

A.shall                 B.will            

C.should                D.ought

(   )4.He is tall, _____ his son is short.

A.when                B.or                

C.while                D.and

(   )5.In our life, we may fail many times, but we should never_____.

A.shut off           B.give up            

C.take away            D.run out

(   )6.She bought a skate board online _____ she saved a lot of time.

A.so that            B.as soon as        

C.such that            D.no matter

(   )7.Every student is _____ to obey the school rules.

A.suppose            B.supposed        

C.should                D.ought

(   )8.A farmer in England used animal waste to _____ his machine.

A.manage            B.use            

C.run                D.start

(   )9.You ought to return the book to the school library _____. Other students will borrow it.

A.at times            B.in time            

C.on time                D.at the same time

(   )10.I always enjoy visiting London._____ I wouldn’t like to live there.

A.Because            B.So                

C.But                D.And


Ⅱ.情景交际。(5分)

根据对话内容,用方框中所给的句子补全对话,其中有两项是多余的。

A:Hey, Judy. Don’t forget to turn off the lights.  11  

B:Oh,I know.I usually do that. I was just in a hurry. How come you’re so interested in the environment, Jack?

A:I always have been.Lots of people think there’s nothing they can do, but I just read this book about it, and there are lots of things the average person can do.

B:Like what?

A:Well, you should turn off the shower when you’re washing your hair.

B:  12  

A:You wouldn’t?

B:No,I have very short hair. I’m only in the shower for a few minutes.

A:  13  

B:What else does it say?

A:It says you should take your own bags when you go food shopping.

B:Oh, that’s not difficult.  14  What else?

A:Hmm.Here’s a good one. It says people should stop riding in cars and start riding bikes.

B:Oh, I’ll never do that! Can you see me riding 45 minutes to and from school every day?

A:Well, I think the environment is really important.  15  

B:Yes, and you also live close to school!

A. It saves electricity.           B.What can we do for that.

C. Oh, I’ll never do that.                           D.I wash my hair every day.

E. Well, every minute helps.                  F. I can do that.

G. Besides, I like riding my bike.

11.______  12.______  13._______ 14._______ 15._______


Ⅲ.完形填空。(10分)阅读短文,从A、B、C、D四个选项中选出能填入文中空白处的正确答案。

Some people say they have a solution to the problems of car crowding and pollution. In many cities, hundreds of people  16   bikes to work every day. In the New York City, some bike riders have even founded a group: Bike for a Better City. They say if more people ride bikes to work, there would be  17   cars and less dirty air.

For several years this group has tried to gather help for bike riders. They want to have special roads  18   bikes only, because when bikes and cars use the same roads, there may be accidents. Bike for a Better City thinks if there were bike roads, more people would use bikes.

But no bike roads have been established  19  . Not everyone thinks it is a good  20  . Drivers don’t like it, and some shop owners don’t like it,  21  . And most people live  22   far from the city to travel by bike. Still,  23   has been done about it. On Saturdays and Sundays, the largest open park in New York is  24   to cars, and the roads may be used by bikes only, but the group still says this is not enough and goes on fighting  25   bike roads. I think there will be more bike roads in the future.

(   )16.A.on                B.ride                        C.by                    D.take(   )17.A.fewer            B.less                        C.many                D.more(   )18.A.until            B.for                       C.as                    D.of(   )19.A.yet                B.already                        C.still                D.once(   )20.A.hope            B.way                        C.help                D.idea(   )21.A.so                B.and                        C.also                D.either(   )22.A.very            B.quite                        C.too                D.so(   )23.A.everything        B.something                    C.anything            D.nothing(   )24.A.closed       B.open              C.opening           D.closing(   )25.A.get                B.to get                         C.ask                D.to ask
Ⅳ.阅读理解。(30分)(A)At present, too much carbon dioxide(二氧化碳) makes the earth warmer and warmer and causes terrible effect to human beings. To save our planet, to save ourselves, a new lifestyle called low-carbon life(低碳生活) becomes popular. Low carbon means low energy and no waste. It is necessary for everybody to learn to live a low-carbon life.To live a low-carbon life, we’d better save energy as possible. Turn off the lights and TV whenever they are not needed. If possible, use cold water to wash clothes or dishes. Take a short shower and try to take a cold one when the weather gets warm. Don’t do the cooking with electricity.To live a low-carbon life, we should eat less meat. Everybody knows eating too much meat makes people fat and easy to have heart disease, but maybe you don’t know keeping animals for food produces even more carbon dioxide than all the cars in the world, and being a vegetarian can help reduce one and a half tons of carbon dioxide a year. Maybe it is a little difficult, but it’s really necessary.To live a low-carbon life, we are supposed to do less shopping. When we go shopping, we may drive a car or take other transportations. On the one hand, these machines pollute the air and waste energy. On the other hand, most of us always buy some useless things because of some advertisements. It is not only a waste of money but also causes trouble to the earth, because as you know, making everything will produce carbon dioxide more or less.There are many other ways to live low-carbon life, such as recycling things, planting trees and reusing textbooks. If we can keep it a habit in our daily life, the earth will become a safer planet for us to live on.根据短文内容,选择正确答案。(   )26._____ makes the weather on the earth get warmer.、A. Little rubbish          B. A waste of money   

C. Too much carbon dioxide     D. A waste of water(   )27.We can _____ to save energy in our daily life.A. use less electricity                    B. go to sleep with lights on  C. wash clothes with hot water     D. drive car to work(   )28.The underlined word “it” in the third paragraph means _____.A. eating less meat                       B. having heart disease  C. keeping animals for food              D. eating less vegetables(   )29.We should do less shopping because _____.A. wasting money causes trouble to people   B. the advertisements are sometimes misleading   C. the less you shop, the less carbon dioxide will be produced   D.some of the things you bought are useless.(   )30.If everybody lives a low-carbon life, _____.A.we will waste more energyB.there will be less carbon dioxideC.the earth will become a dangerous place to live onD.there will be more carbon dioxide

(B)

Animals United is a 3D German cartoon which is directed by Reinhard Klooss and Holger Tappe. It is a story about animals that get together to find water. Along their journey, lots of funny things happen, and of course, they have a lot of adventures.

The animals in the grasslands in Africa are waiting for the coming flood. However, this year's flood seems to come later than in other years. The animals become upset and worried. At the same time, some animals from other places come to the grasslands to look for peace. However, the situation seems worse because the water is becoming less and less. So they decide to look for the river.

Finally, they find the reason why they don’t have any water to drink. A dam(坝) has been set up so that humans can have a better life. After a long fight with humans, they let the world know that animals are in danger.

This film is about environmental matters. The humans are the bad and the animals are the good. This film is to give humans a warning that they must not destroy the homes of animals or damage nature in order to improve their own life. Humans should know that animals also have their own world.

根据短文内容,选择正确答案。(   )31.The story of Animals United took place _____.A. in Asia         B. in Africa          C. in America        D. in Germany(   )32. The animals become worried because _____.A. the year’s flood is comingB. they will have no water to drinkC. there is going to be a fight with humansD. their grasslands have been taken up(占领) by other animals(   )33. Along their journey to look for the river, the animals find_____.A. humans have set up a dam                 B. the river is becoming dryC. all the animals are in danger                D. the world is getting warmer(   )34. Humans are warned not to_____.A. damage nature                           B. kill any animalsC. pollute the environment                    D. do harm to the grasslands(   )35. The story of Animals United mainly tells us_____.A. it’s our duty to protect animalsB. humans and animals should live in peaceC. humans should care about the environmentD. it’s time to think about animals' living environment(C)It’s important to learn things about protecting environment. Here’s a 4Rs rule for us.

·Reduce

If you want to reduce waste, you should use things wisely (明智的). A large number of trees are being cut down to make paper. If everyone uses paper carelessly and then throws it away, soon we would not have any trees left. Some other things are also being wasted, and people don’t know what to do with waste in big cities, so it’s necessary to reduce waste.

·Reuse

You should always think of reusing the usable (可用的) things before throwing them away. Give your clothes or things you don’t use to the poor. In a family, you may pass such clothes on to your younger brothers or sisters.

·Recycle

Bottles, cans and paper can easily be recycled. By doing so we save lots of time and money, for example, cola cans are sent to a factory, where they’re smashed flat(压平)and smelted (熔化), and the metal things are made into new cola cans.

·Repair

If one of the legs of your table is broken, you can repair it. If you want to change for better ones, it’s better for you to sell the old ones or give them to other people who can use them after doing some repair.

根据短文内容,选择正确答案。(   )36.The “Reduce” rule mainly requires us _____.A.to use things wisely                B.to cut down many treesC.to use paper carelessly                D.to use more and more things(   )37.What’s the right order of recycling cola cans?a.smash them flat        b.collect the used cansc.smelt them            d.send them to a factoryA.a-b-c-d            B.d-c-b-a            C.b-d-a-c            D.b-d-c-a(   )38.The “Reuse” rule mainly requires us _____.A.to throw away the old clothesB.to collect waste paper and soft drink cansC.to use both sides of paperD.to give the old but usable things to the poor(   )39.Which sentence is about the “Repair” rule?A.When you leave a room, turn off the lights.B.Take a cloth bag when you go shopping.C.Don’t use plastic bags.D.If your chair is broken, you can repair it.(   )40.Which is the best title for this passage?A.A 4Rs Rule                B.Protect the EnvironmentC.Save Energy              D.Good Habits


第三部分 语言知识运用(25分)Ⅰ.词汇。(10分)(A) 根据句意及汉语提示完成句子。1.Never__________ (放弃) studying,you’ll succeed one day.2.Remember to __________ (关掉)all the electricities when you leave the room.3.The bus has six __________ (轮子).4.My shirt was _________ (干燥的,干的)after several minutes under the sun.5.There is a__________ (深的) hole in the tree. Maybe there are some animals in it.(B) 根据句意,用所给单词的适当形式填空。6.I asked him if he would help me and he_____ (nod).7.They had an_______ (agree)never to talk about work at home.8.She began to explain her plan of_______ (act) to the group.9.The new medical _______ (technology) can save more people’s lives.10.Do you _______ (require)anything else?
Ⅱ.英汉互译。(5分)11.你们是怎样处理塑料袋的?How do you deal with _____ _____?12.均衡的饮食和有规律的运动被视为健康的必要条件。Balanced diet and regular sports_____ _____ _____requirements for health.13.当你离开教室的时候, 应该随手关灯。You _____ _____ turn off the lights when you leave the classroom.14.说比做更容易。_____ said than _____.15.行动胜于言辞。Well, _____ speak louder than _____.
Ⅲ.书面表达。(10分)“保护环境,人人有责”,请以How to Be a Greener Person 为题,写一篇有关环保的短文,并适当发表你的看法。(80词左右)





听 力 材 料

Unit 2  Topic 3

Ⅰ.听句子,根据所听句子的内容和所提的问题,选择符合题意的图画回答问题。每个句子读一遍。

1.Don’t throw rubbish here and there.

2.What beautiful flowers! I want to pick some of them.

3.W: There’s too much noise in the street. It makes me uncomfortable.

4.People have cut down too many trees. It causes the terrible sandstorm.

5.W: In my hometown, people use the wind to produce electricity.

Ⅱ.听对话,选择正确答案。每段对话读两遍。

6.M: Jenny, what should you do to help protect the environment?

W: I reuse plastic bags.

7.M: Is the article about pollution?

W: Yes, it says air pollution has become a serious problem in China.

8.M: I’ve written a book on the environment.

W: That’s great. We should spread the message about protecting the environment.

9.W: Jane has never spat in public.

M: Oh, that’s good. I heard she joined an environmental organization.

10.W: I want to do volunteer work. What can I do?

M: I think you can help spread the message about protecting the environment.

Ⅲ.听短文,选择正确答案。短文读两遍。

Scientists are trying to make the desert into field land again. They want to bring water to the desert, so people can live there and grow crops. They are learning a lot about the desert. But more and more land is becoming desert all the time. Scientists may not be able to change the desert in a short time.

Why is more and more land becoming desert? Scientists think people are doing bad things to the earth.

Some places on the earth don’t get much rain. But they still haven’t become desert. This is because some green plants are growing there. Small green plants and grass are very important to dry places. Plants prevent the sun from making the earth dry. Plants prevent the wind from blowing the dirt away. When a bit of rain falls, the plants hold the water. Without plants, the land can become desert easily.

Ⅳ.听短文,选择最佳答案。短文读两遍。

Today is Earth Day, April 22nd. It's sunny. My classmates and I went to the park to do some cleaning there. Early in the morning, we started out by bike. We began to work as soon as we got there. First we collected the rubbish near the lake and in the woods and put it in the dustbins. Then we put up some notices to tell people not to destroy nature. At the same time we kept on telling the visitors the importance of protecting the environment. We said goodbye to the workers of the park and went home after we had cleaned the park. 
   Though we were very tired, we felt very happy. 



参考答案及解析Unit 2  Topic 3第一部分  听力Ⅰ.1.A  2.A  3.C  4.B  5.BⅡ.6.C  7.A  8.B  9.B  10.CⅢ.11.A  12.B  13.C  14.A  15.CⅣ.16.B  17.A  18.C  19.C  20.B第二部分  基础知识运用Ⅰ. 1.B  考查一般现在时指将来。表示按日程表将要发生的动作或事件。故选B。2.D  考查并列句。表示转折关系,or在这里意为“否则”。故选D。3.D  考查情态动ought to,意为“应该,应当”,无人称、数和时态变化,后接动词原形。ought to的疑问句形式是把ought提前。故选D。4.C  考查并列句,本句表示转折关系,while有“而”的意思。故选C。5.B  shut off意为“关掉”;give up意为“放弃”;take away意为“拿走”;run out意为“用尽”。根据句意可知,应用give up。故选B。6.A  so that 引导目的状语从句。故选A。7.B  be supposed to意为“应该,理应”,同should同义,但形式不同。ought to是情态动词, 后接动词原形。故选B。8.C  run意为“奔跑;控制;管理”,此处为“发动,使工作”的意思。其他选项均与题意不符。故选C。9.C  at times有时;in time 及时;on time准时;at the same time 同时。只有C项符合题意。故选C。10.C考查并列句,句意为“我总是乐意去参观伦敦,但我并不想住在那里。”前一分句与后一分句是转折关系,应该用but。故选C。Ⅱ.11.A  12.C  13.E  14.F  15.GⅢ. 16.B  由于选项在本句中作谓语而谓语应为动词,故排除A、C两项。ride bikes to work骑自行车去上班。17.A  本句的if从句提示如果有更多的人骑自行车上班的话,那么就会减少汽车的数量以及对空气的污染。car是可数名词,故选能修饰可数名词的few的比较级。18.B  考查have … for 表示“有为自行车而专设的特殊道路”。for在这里表示目的。19.A  本句中有否定词no, 而yet多用于现在完成时的否定句和疑问句中。20.D  根据上下文看此处的含义是“并不是每个人都认为这是个好主意”。分析选项,只有idea符合题意。21.D  either用于否定句末,表示“也”的含义;also也表示“也”之意,但用于肯定句中。22.C  考查too … to … 结构,表示“太……而不能……”。23.B  根据上下文此处应填something“有些事情”,用于肯定句;anything“任何东西”,用于否定句和疑问句;nothing“没有什么”,表示否定。24.A  be closed to表示“对……关闭”,而be open to表示“对……开放”。由Somethinghas been done about it. 可看出,此处应是禁止汽车入内的,所以选择A项。25.B  考查用不定式作目的状语,而D项不符合题意,所以选择B项。Ⅳ.(A)26.C  由At present, too much carbon dioxide makes the earth warmer and warmer and causes terrible effect to human beings.可知,太多的二氧化碳让地球变暖。故选C。27.A  由第二段可知,在我们的日常生活中节约能源的方式有许多,A项是少用电,符合题意。故选A。28.A  在第三段可知,it指代eating less meat意为“少吃肉”。故选A。29.C  由第四段可知,我们应该少购物,因为我们去购物就要乘坐交通工具,这些交通工具就会产生空气污染。故选C。30.B  如果人人都能低碳生活,二氧化碳的排放量就会少,就有利于环保。故选B。(B)31.B  由The animals in the grasslands in Africa are waiting for the coming flood.可知。故选B。32.B  由第二段The animals in the grasslands in Africa are… The animals become upset and worried.可知。故选B。33.A  由第三段they find the reason...have a better life可知。故选A。34.A  最后一段This film is to...in order to improve their own life.可知。故选A。35.C  由主旨“本文介绍了一部关于动物寻找水的电影,让人类知道动物也需要它们自己的世界,人类应该照顾好环境。”可知。故选C。(C)36.A  If you want to reduce waste, you should use things wisely. 一句可找到答案。故选A。37.C  可乐罐子的回收再利用程序应为: 收集废旧的罐子—送到工厂—压平—熔化。故选C。38.D  根据文章:A项扔掉旧衣服不符合再利用原则;B项应属于Recycle原则;C项属于Reduce原则。故选D。39.D  repair意为“修理,修补”。D项的意思为“如果椅子坏了,你可以修理它。”故选D。40.A  本文的中心思想主要围绕的是4R原则。第三部分  语言知识运用Ⅰ.(A)1.give up  2.shut off  3.wheels  4.dry  5.deep(B)6.nodded  7.agreement  8.action  9.technology  10.requireⅡ.11.plastic bags 12.are regarded as  13.ought to  14.Easier, done  15.actions, wordsⅢ.参考范文:How to Be a Greener PersonIt’s our duty to protect the environment around us. The three Rs—reduce, reuse and recycle—are important. I think we’d better not buy bottles or boxes which people can only use once. We should turn off the lights when we are not using them. We can give old clothes to others to reuse them. When we go shopping, we’d better take a cloth bag rather than use plastic bags. We shouldn’t throw things away if they can be reused, repaired or recycled. It’s important for us to protect animals and plants. We are supposed to prevent the factory from pouring waste water into rivers, lakes and so on. If everyone is doing that, our world will become more and more beautiful.

下载提示



Unit 2 Topic 3 单词听力+课文朗读+单元测试(含听力)下载

长按识别二维码,下载资料

电脑下载请复制下述链接下载
下载链接:http://jazpan.com/view/861.html


●● END ●

怎么获取配套视频练习等资料?


扫描下方二维码

免费领取方式

点击左下方阅读原文

即可领取全套资料

图文来自网络,版权归原作者,如有不妥,告知即删

点击阅读原文下载全册PPT课件动画教案习题朗读试卷电子课本整套资料

您可能也对以下帖子感兴趣

文章有问题?点此查看未经处理的缓存