七年级英语下册阅读理解专项练习经典经典1

七年级英语下册阅读理解专项练习经典经典1

一、七年级英语下册阅读理解专项目练习（含答案解析）

1．阅读理解

London has a population of over 7, 000, 000. From about the year 1800 until World War Ⅱ, London was the biggest city in the world. But now there are many cities which are much bigger than it.

London is famous for many things. Tourists （游客）coming from all over the world go to visit its famous buildings, for example, Big Ben. Like many other big cities, London has problems with traffic（交通 ）and pollution（污染） which stop the city from developing. Over one million people use the London underground every day, but there are still too many cars on the streets. The air isn't clear, but it is anyhow cleaner than it was 100 years ago.

For me, the best things about London are the parks. There are five in the city center. But my children's favorite place is Hamleys, the biggest toy shop in the

world.

（1）When was London the biggest city in the world?

A. In 1750. B. In 1850. C. In 1950. D. In the 21st century.

（2）What's the Chinese meaning for “underground” in the passage? A. 隧道 B. 地下 C. 道 D. 地铁

（3）How many people use the London underground every day?

A. Over half of its population.

B. Over three quarters of its population.

C. Over 100, 000.

D. Over 1, 000, 000.

（4）Which of the following is TRUE?

A. The air before was much cleaner than it is now.

通

B. “I” like Hamleys best.

C. There are five parks in the city center.

D. “My” son likes Big Ben very much.

【答案】 （1）B

（2）D

（3）D

（4）C

【解析】【分析】文章大意：本文介绍了伦敦的名胜和伦敦存在的问题。

（1）细节题。根据 From about the year 1800 until World War Ⅱ, London was the biggest city in the world. But now there are many cities which are much bigger than it.可知从19世纪到1939年伦敦是世界上最大的城市。故选B。

（2）词义猜测题。根据 London has problems with traffic（交通 ）and pollution（污染） which stop the city from developing. Over one million people use the London underground every day, but there are still too many cars on the streets.伦敦有交通问题并且污染阻碍城市的发展。又有一百多万人每天用——，但是在街道里仍然太多的轿车。可知与街道对比，应该是指的交通工具地铁，故选D。

（3）细节题。根据 Over one million people use the London underground every day 有一百多万人每天用伦敦地铁可知，故选D。

（4）细节题。根据 For me, the best things about London are the parks. There are five in the city center. 可知在城市里有5个公园。故选C。

【点评】考查阅读理解。本文涉及细节题和词义猜测题，细节题注意从文中找答案；词义猜测题需要联系上下文，推断出词义。

2．阅读理解

When you are in England, you must be very careful in the streets because the traffic goes on the left. Before you cross the street, you must look to the right first and then the left.

If the traffic lights are red, the traffic must stop. Then the people on foot can cross the road.

If the lights are green, the traffic can go and people on foot mustn't cross.

In the morning and in the evening when people go to or come back from work, the streets are very busy. The traffic is the most dangerous then.

When you go by bus in England, you have to be careful, too. You must always remember the traffic moves on the left. So you must be careful. Have a look first or you'll go the wrong way.

In many English cities, there are big buses with two floors. You can sit on the second floor. From there you can see the city very well. That'll be very interesting.

（1）Before you cross a street in London, you must look to ________.

A. only the right side

B. only the left side

C. the left first and then the right

D. the right first and then the left

（2）When you drive a car in England, you must ________.

A. drive on the left B. drive on the right C. ignore the traffic lights D. go very quickly

（3）If the traffic lights are green, the traffic ________.

A. can go B. must be careful C. mustn't

cross D. must stop

（4）Which of the following is right?

A. After you cross the street, you must look to the left first and then the right.

B. If the lights are red, the traffic mustn't stop.

C. You must drive cars on the left in England.

D. In the morning and in the evening when people go to or come back from work, the traffic is not dangerous at all.

【答案】 （1）D

（2）A

（3）A

（4）C

【解析】【分析】文章大意：本文介绍了伦敦的交通规则和交通工具，还告诉我们什么时候伦敦街道的交通比较危险。

（1）细节理解题，根据 Before you cross the street, you must look to the right first and then the left. 可知在你横穿马路之前，你必选先看右边然后再看左边。故答案是D。

（2）细节理解题，根据 You must always remember the traffic moves on the left. 可知你必须总是要记住交通是靠左行驶的。故答案是A。

（3）细节理解题，根据 If the lights are green, the traffic can go.可知如果灯绿

了，交通就可以运行了。故答案是A。

（4）细节理解题，根据 You must always remember the traffic moves on the left. 可知你必须总是要记住交通是靠左行驶的。因此C是正确的。故答案是C。

【点评】考查阅读理解，本题主要涉及的是细节理解题，细节题要注意从文中寻找答案。

3．阅读理解

Spring comes back again. It's the best time for children to fly kites outside. Look! There are different styles of kites in the sky. How beautiful and lovely!

Kite facts

Kites all have long strings（绳子）. They keep kites from flying away. Kites can fly up high with a good wind. Each of them always has a tail. It makes the kite beautiful and balanced（平稳的）.

Useful kites

Kites weren't just for fun. People also used them to do many other things. Before planes came out, some people put cameras on kites to take photos. 100 years ago some Americans used kites to learn about weather. Later some people used them for fishing.

How to fly

Never fly kites in the street or on the road. We can find a big playground or an open place. When we fly kites, we should be far away from wires（电线）. If our kites are in a tree, don't climb to get it. Maybe we'll fall off. Ask our parents for help.

（1）Which season is the best time for kite flying according to the passage?

A. Winter. B. Autumn. C. Summer. D. Spring.

（2）After kites came out, people used them to ________.

①learn about weather ②catch fish

③grow wheat ④take photos ⑤feed birds

A. ①③④ B. ②③④ C. ①②④ D. ②④⑤

（3）Where can children fly kites?

A. On the playground. street. D. In the forest.

B. Near the wires. C. In the

（4）If Sandy's kite falls onto a tall tree, what should she do?

A. Climb to get it quickly. B. Call the police.

C. Ask her parents for help. D. Cut down the tree.

【答案】 （1）D

（2）C

（3）A

（4）C

【解析】【分析】大意：文章主要介绍了一些关于风筝的事实、风筝的有用之处和如何放风筝。

（1）细节理解题。根据第一段 Spring comes back again. It's the best time for children to fly kites outside. 可知，春天是放风筝最好的季节。故选D。

（2）细节理解题。根据第三段 some people put cameras on kites to take

photos. 100 years ago some Americans used kites to learn about weather. Later some people used them for fishing. 可知，人们用风筝带着照相机照相、了解天气和钓鱼， ①②④ 表述正确。故选C。

（3）细节理解题。根据第四段 We can find a big playground or an open place. 可知，孩子们可以在操场或者开放的地方放风筝。故选A。

（4）细节理解题。根据最后一句 Ask our parents for help.可知，当风筝挂在树上时，我们应该向父母寻求帮助。故选C。

【点评】考查阅读理解。细节题要注意从文中寻找答案。

4．阅读理解

Can trees talk? Yes, but not in words. Scientists have reasons to believe that trees do communicate with each other. Not long ago, researchers learned some surprising things. Some caterpillars（毛毛虫） attacked a willow tree（柳树） in the woods. The tree changed the chemistry of its leaves and the leaves tasted so terrible that the caterpillars stopped eating them. Then even more surprising, the tree sent out a special vapour （蒸气） a signal causing its neighbours to change the chemistry of their own leaves and make them less tasty.

Communication, of course, doesn't need to be always in words. We can talk to each other by smiling, raising our shoulders and moving our hands. We know that birds and other animals use a whole vocabulary of songs, sounds and

movements. Bees dance their signals, flying in certain patterns that tell other bees where to find nectar（花蜜） for honey. So why shouldn't trees have ways of sending messages?

（1）From the passage we know that caterpillars .

A. like willow trees B. enjoy eating fallen leaves

C. can talk to other caterpillars D. can send out a special vapour

（2）Caterpillars will stop eating willow tree leaves which .

A. have a chemical change and become tasteless B. have a pleasant taste

C. are being attacked D. are communicating

（3）What makes the researchers more surprised is that .

A. caterpillars stop eating the willow tree's leaves

B. the willow tree can send out a special vapour

C. trees can talk to each other by their words

D. birds and other animals all use vocabularies

（4）According to the passage, bees communicate with each other by .

A. talking B. making unusual sounds C. flying in certain

patterns D. singing songs

【答案】 （1）A

（2）A

（3）B

（4）C

【解析】【分析】本文讲述的是树和树之间，动物和动物之间也是群在沟通交流的。

（1）推理题。根据 Some caterpillars（毛毛虫） attacked a willow tree（柳树） in the woods 可知毛毛虫喜欢柳树 ，故选A。

（2）细节题。根据 The tree changed the chemistry of its leaves and the leaves tasted so terrible that the caterpillars stopped eating them 可知当发生化学变化，变得无味时毛虫会停止吃柳树的叶子。 ，故选A。

（3）细节题。根据 Then even more surprising, the tree sent out a special vapour 可知 更令人惊讶的是，这棵树散发出一种特殊的蒸汽，故选B。

（4）细节题。根据 Bees dance their signals, flying in certain patterns that tell

other bees where to find nectar（花蜜） for honey 可知蜜蜂以某种模式飞行来彼此交流 ，故选C。

【点评】考查阅读理解。本文涉及细节题，细节题要注意从文中寻找答案。

5．阅读短文，从下面每小题的A、B、C、D四个选项中选出最佳选项。

Once upon a time, a proud （骄傲的） Swallow lived in a large tree. He liked his colorful feathers （羽毛） and his long tail so much that he believed nothing could be better than them. One day he saw a Crow and thought. \"How silly this bird is! All his feathers are black.\" He looked at himself lovingly and enjoyed his own feathers.

Just then, the crow flew and sat on the same branch as the Swallow. The Swallow said, \"All your feathers are black and your tail is so short.\" The Crow smiled and said. \"But they help me fly.\" The Swallow said. \"So do mine. But look at how beautiful they are!\" He spread （展开） his wings and flew a little closer to the Crow. The Crow saw that the Swallow had lots of blue feathers and some white and pink ones, too. He looked at his own feathers and thought, \"It's true. The Swallow's feathers are much prettier than mine.\"

The Crow said, \"Swallow, you're right. You have lovely feathers and a long tail,

but only in summer. Your little feathers cannot keep you warm in winters at all. While you shiver （颤抖） in the cold, my thick feathers keep me warm in the cold winters.\"

（1）The Swallow was proud of his ________.

A. flying skills B. strong body C. beautiful

voice D. feathers and tail

（2）When the Swallow said the Crow's feathers and tail weren't beautiful, the Crow ________.

A. became angry B. smiled and explained

C. flew away quickly D. became worried and sad

（3）The Crow thought the Swallow's feathers ________.

A. were really colourful B. looked silly and ugly

C. were as beautiful as his own D. were not long enough

（4）What does the underlined sentence mean?

A. My feathers are black, too. B. My tail is as long as yours.

C. My feathers and tail help me fly, too. D. My feathers and tail are colourful, too.

（5）What does the story want to tell us?

A. Birds of a feather flock （聚集） together.

B. Don't be proud of something that's of little use.

C. Find out our own problems and solve them quickly.

D. Don't make friends with people who are too proud.

【答案】 （1）D

（2）B

（3）A

（4）C

（5）B

【解析】【分析】文章大意：从前，一只骄傲的燕子住在一棵大树上。他非常喜欢他的彩色羽毛（羽毛）和他的长尾巴，以至于他相信没有什么比它们更好的了。有一天，他看见一只乌鸦，他看不起乌鸦，认为乌鸦儍，但是乌鸦却不这么认为，他说他的羽毛可以

帮着取暖，但是燕子额羽毛去不能。

（1）细节理解题，根据 He liked his colorful feathers （羽毛） and his long tail 可知燕子为他的羽毛和尾巴而骄傲，故答案是D。

（2）细节理解题，根据 The Crow smiled and said. \"But they help me fly.\" 可知，当燕子嘲笑乌鸦的时候，乌鸦微笑着解释，故答案是B。

（3）细节理解题，根据 It's true. The Swallow's feathers are much prettier than mine.\" 可知，乌鸦认为燕子的羽毛比自己的漂亮，真的好看，故答案是A。

（4）句意猜测题，根据 But they help me fly.\" The Swallow said. \"So do mine. 可知，划线句子的意思是：我的羽毛和尾巴也能帮我飞翔，故答案是C。

（5）主旨大意题，根据文章内容可知，乌鸦的羽毛尽管不漂亮但是可以保暖，而燕子的羽毛虽然漂亮但是不保暖，所以不要为一点点有用的东西而感到骄傲，故答案是B。

【点评】考查阅读理解。本文涉及细节理解题、词义猜测题和主旨大意题。细节理解题要可以直接从文中寻找答案；句意义猜测题，需要根据单词所在的语境，进行合理想象，确定单词的意思；主旨题需要通读全文，了解大意之后找出中心思想。

6．阅读理解

A tornado happened in Illinois, the USA on April 9th. The tornado hit the ground at around 7:00 p. m. on Thursday evening. According to a report, eight of the 150 local people were taken to hospitals after the tornado. All the people

there were evacuated（撤离）, and the power was off across the area. The Red Cross and Salvation Army built a rescue centre in a high school.

Chad Connell, the Chief of Kirkland Community Fire District, said he watched the tornado moving toward the town from his house. “I've never seen anything like it in my life,\" he said, almost lost for words.

It is reported that about 20 houses in Ogle County were badly damaged or even destroyed. Luckily, no people were killed or badly hurt there. It is also reported that 12 people were trapped（被困住） in a restaurant which collapsed（坍塌） in the tornado in Rochelle, about 20 miles south-west of Fairdale. Raymond Kramer, 81, was one of them. He said they were trapped for 90 minutes before the emergency crews were able to rescue them.

\"When the tornado hit, we all got a dust（灰尘） bath,\" Raymond told a reporter. \"Everyone there got covered with dust. We are so lucky that we are finally saved. \"

（1）The first paragraph told us the following facts EXCEPT .

A. why the tornado happened happened

B. when the tornado

C. where the tornado happened D. what happened after the tornado came

（2）According to the passage, it was the time that Chad

Connell experienced a tornado in his life.

A. last B. first C. second D. third

（3）What might be the 12 people doing when they were trapped?

A. Sleeping. B. Having dinner. C. Taking a

shower. D. Saving other people.

（4）What's the best title for the passage?

A. A tornado hit Illinois B. What to do after a tornado

C. What a tornado brings people D. People trapped in a tornado

【答案】 （1）A

（2）B

（3）B

（4）A

【解析】【分析】主要讲了龙卷风袭击了伊利诺斯州时的情景。

（1）细节题。根据A tornado happened in Illinois, the USA on April 9th；eight of the 150 local people were taken to hospitals after the tornado. All the people there were evacuated（撤离）, and the power was off across the area. The Red Cross and Salvation Army built a rescue centre in a high school. 可知龙卷风发生在美国的Illinois，时间是4月9日，龙卷风后人们被送到医院，并且撤离，电被切断，即龙卷风后发生了什么，故选A。

（2）细节题。根据I've never seen anything like it in my life，可知他生活中从没有看见像这次龙卷风一样的，所以是第一次，故选B。

（3）推断题。根据It is also reported that 12 people were trapped（被困住） in a restaurant which collapsed（坍塌） in the tornado in Rochelle, about 20 miles south-west of Fairdale.可知12个人被困在餐馆里，所以他们可能在吃晚饭，故选B。

（4）主旨题。根据全文可知主要讲了龙卷风袭击了伊利诺斯州，故选A。

【点评】考查阅读理解，主要考查细节题，注意从文中仔细寻找答案。

7．阅读理解

There is little rain in deserts. Because deserts are so dry, they have no\"quilt\" to help stop the soil from going away. As a result, they may get very hot during the day with the Sun shining, but don't hold the heat overnight. Many deserts can

quickly get cold once the Sun goes down. Some deserts can reach the temperature of over 100 degrees F during the day and then drop below freezing（32 degrees F）during the night.

The largest hot and dry desert in the world is the Sahara Desert in North Africa. The Sahara is a sandy desert with great sand hills. It covers over 3 million square miles of Africa. Other large deserts include the Arabian Desert in Western Asia, the Gobi Desert in northern China and southern Mongolia, and the Kalahari Desert in Africa.

Animals that live in the desert are also used to needing little water. Many get all the water they need from the food they eat. Other animals keep water that they can use later. The camel stores up fat in its hump while other animals keep something they need in their tails.

Only certain types of plants can live in the terrible environment of the desert. You won't see a lot of tall trees in the desert. Most plants have a way to keep water in their leaves or trunks so they can live a long time without water.

Now deserts cover around 20% of the world's land, but they are growing. This is called desertification and is caused by different reasons including human activities. The Sahara Desert is growing larger and larger each year. What should we do with it?

（1）How is the weather during the night in the desert?

A. Hot. B. Cold. C. Cool. D. Warm.

（2）Where does the camel store up fat?

A. In its hump. tail. D. In its back.

B. In its stomach. C. In its

（3）Why WON'T we see a lot of tall trees in the desert?

A. Because there're few people there. B. Because the Sun shines there.

C. Because the environment there is terrible. D. Because there's a lot of rain there.

（4）How much of the land do deserts cover in the world?

A. About one fifth. B. Less than 10%. C. Two

fifths. D. More than 20%.

（5）Is the Sahara Desert growing or not?

A. Nobody knows it. B. It is growing. C. It is not

growing. D. It is losing（减少）.

【答案】 （1）B

（2）A

（3）C

（4）A

（5）B

【解析】【分析】主要讲了对沙漠的概述。

（1）细节题。根据Some deserts can reach the temperature of over 100 degrees F during the day and then drop below freezing（32 degrees F）during the night.可知沙漠晚上是寒冷的，故选B。

（2）细节题。根据The camel stores up fat in its hump可知骆驼从驼峰上储存脂肪，故选A。

（3）细节题。根据Only certain types of plants can live in the terrible environment of the desert. You won't see a lot of tall trees in the desert.可知因为沙漠环境恶劣，所以沙漠里看不见许多高树，故选C。

（4）细节题。根据Now deserts cover around 20% of the world's land可知沙漠占了世界的20%，即五分之一（one fifth），故选A。

（5）细节题。根据The Sahara Desert is growing larger and larger each year.可知撒哈拉沙漠正在增大，故选B。

【点评】考查阅读理解，主要考查细节题，注意从文中仔细寻找答案。

8．阅读理解

Roy is a school boy. He often goes out to play after school. But he never gets home late for supper. It was his eleventh birthday last Friday. But his parents didn't see him at supper time. They waited and waited, but Roy didn't come. At about seven o'clock, they felt very worried. They had to go out to look for their son here and there, but they couldn't find him. At last they went to the police station for help. To their great surprise, when they came back home, they saw Roy sitting at the supper table and enjoying the birthday cake, \"Why didn't you come upstairs（上楼）to watch TV with me, Dad? \"said Roy when he saw his father.

（1）Roy often after school.

A. does his homework play D. gets home late

B. watches TV C. goes out to

（2）The Chinese meaning of the word\"worried\"is .

A. 气愤的 的 D. 担心的

B. 疲倦的 C. 高兴

（3）Roy's parents went to for help.

A. the school B. the police station C. the teacher's

house D. his friend's house

（4）Which of the following is right?

A. Roy went out to play with his friends on his birthday.

B. Roy came back before 7 o'clock that evening but his parents didn't know.

C. Roy's parents went to the police station and found Joy there.

D. Joy was upstairs and ate the birthday cake by himself.

【答案】 （1）C

（2）D

（3）B

（4）B

【解析】【分析】本文介绍了Roy的父母以为他回家晚了，到处寻找他，其实那天晚上7点以前罗伊回来了，但他的父母不知道。

（1）细节题。根据 Roy is a school boy. He often goes out to play after school. 可知他经常放学后出去玩，故选C。

（2）词义猜测题。根据 they felt very worried. They had to go out to look for their son here and there 他们很担心。他们不得不出去找他们的儿子，可知worried是担心的，故选D。

（3）细节题。根据 they went to the police station for help 可知他们去警察局寻求帮助，故选B。

（4）推理题。根据 they saw Roy sitting at the supper table and enjoying the birthday cake可知那天晚上7点以前罗伊回来了，但他的父母不知道 ，故选B。

【点评】考查阅读理解。本文涉及细节题、推断题，词义猜测题，细节题要注意从文中寻找答案；推断题需要联系上下文，推断出需要的信息，词义猜测题需要根据上下文提炼相关信息锁定词意。

9．阅读理解

If you go into the forest with your friends, stay with them. If you don't, you may get lost. If you get lost, this is what you should do. Sit down and stay where you are. Don't try to find your friends—let them find you. You can help them find you by staying in one place. There is another way to help your friends or other people to find you. You can shout or whistle（吹口哨）three times. Stop. Then shout or whistle three times again. Any signal（信号）given three times is a call

for help.

Keep shouting or whistling. Always three times together. When people hear you, they will know that you are not just making a noise for fun. They will let you know that they have heard your signal. They will give you two shouts or two whistles. When a signal is given twice, it is an answer to a call for help.

If you don't think that you will get help before night comes, try to make a little house with branches（树枝）. Make yourself a bed with leaves and grass.

When you need some water, you have to leave your little house to look for it. Pick off small branches and drop（丢）them when you walk, then you can go back again easily. When you are lost, the most important thing is to stay in one place.

（1）If you get lost in the forest, you should _________.

A. try to find your friends B. stay in one place and give signals

C. walk around the forest D. shout as loudly as possible（尽量大声）

（2）People shout ______ to answer a call for help.

A. once B. twice C. three

times D. four times

（3）By saying the underlined sentence（Para.4）, the writer thinks it is easy to ______ in the forest.

A. find your way back B. pick off small branches

C. find enough water to drink D. make a little house with branches

（4）The main（主要的）idea of the passage is __________.

A. how to travel in the forest B. how to spend the night in the forest

C. what to do if you want to get some water D. what to do if you are lost in the forest

【答案】 （1）B

（2）B

（3）A

（4）D

【解析】【分析】主要讲了如果在森林里迷路应该怎么办。

（1）细节题。根据Sit down and stay where you are. You can shout or whistle（吹口哨） three times.Stop. Then shout or whistle three times again. Any signal（信号）given three times is a call for help.可知待在原地并且发信号，故选B。

（2）细节题。根据When a signal is given twice, it is an answer to a call for help.可知回应两次是回应求救，故选B。

（3）细节题。根据下划线句子可知当步行时扔下树枝，然后你可以很容易返回，所以作者认为在森林里找回原先的路是简单的，故选A。

（4）主旨题。根据全文可知主要讲了如果在森林里迷路应该怎么办。故选D。

【点评】考查阅读理解。本文涉及细节题和主旨题常考题型，细节题要注意从文中寻找答案；主旨题需要通读全文，了解大意之后找出中心思想。

10．阅读理解

What is the first thing you want to do when you see someone yawn（打呵欠）? You want to yawn, too! Yawning is contagious. Scientists have found that all people yawn. Babies start to yawn even before they are born. When a baby is inside its mother, he or she yawns. When young children are about one year old, they start to yawn when they see others yawning. That's why scientists think yawning is contagious.

But why do we yawn? Well, scientists are not really sure. Some think we yawn because we feel bored. Others believe yawning has something to do with breathing（呼吸）. When there is too much carbon dioxide（ CO2 ） in our bodies, our bodies will tell the brains（大脑） to breathe deeply. That causes a big yawn. In 2007, scientists said people yawned to cool down their brains. These scientists found people yawned more often if they were warmer than others.

Scientists are trying to find out why yawning happens and why it is so contagious. But they are only sure that when one person yawns, everyone else nearby wants to yawn, too.

（1）The underlined word \"contagious\" in Paragraph 1 means__________.

A. 神秘的 B. 疲倦的 C. 可传染的 D. 有帮助的

（2）According to the passage, scientists are not really sure about ______.

A. when people start to yawn B. whether all people yawn

C. whether yawning is contagious D. what makes yawning happen

（3）Which of the following may be the reasons for yawning according to the passage?

①People yawn because they are bored

②People yawn to make them look funny

③People yawn to cool down their brains

④People yawn to cut down carbon dioxide

A. ①③④ B. ②③④ C. ①②③ D. ①②④

（4）We can probably read this passage in a（n）__________.

A. storybook magazine D. e-mail

B. sports news C. science

【答案】 （1）C

（2）D

（3）A

（4）C

【解析】【分析】主要讲了科学家不确定我们为什么打哈欠，但是正在查明打哈欠为什么传染。

（1）细节题。根据What is the first thing you want to do when you see someone yawn（打呵欠）? You want to yawn, too!当你看见他人打哈欠时你也想打哈欠，所以打哈欠是传染的，故选C。

（2）细节题。根据But why do we yawn? Well, scientists are not really sure.可知科学家不确定为什么打哈欠，故选D。

（3）细节题。根据Some think we yawn because we feel bored. Others believe yawning has something to do with breathing（呼吸）. When there is too much carbon dioxide（ CO2 ） in our bodies, our bodies will tell the brains（大脑） to breathe deeply. That causes a big yawn. In 2007, scientists said people yawned to cool down their brains.可知一些人认为我们感到无聊、其他人认为为了减少二氧化碳、科学家说人们为了使大脑冷静，故选A。

（4）细节题。根据全文可知讲了打哈欠，在科学杂志上读到，故选C。

【点评】考查阅读理解，主要考查细节题，注意从文中仔细寻找答案。