专项4 阅读理解（说明文）-北师大版七年级上册期末专项

原创精品资源学科网独家享有版权，侵权必究！ 1 专项 4 阅读理解-说明文 Passage 1 As we all know, there are different kinds of clubs in the US middle schools, such as the music club, the sports club, the chess club and the swimming club. But do you know the homework club? It is a popular club in many US middle schools. More and more students spend (度过) their afternoons in the homework club. The US middle school students need a quiet place to study. But games, computers and TVs are all around kids at home. So the homework club is just for them to do their homework. The club is quiet and it’s also good for students to read their favorite books. Some teachers are there, too. They can answer students’ questions and help with their homework. After the students finish their homework, they can go home. Then they can play games or watch TV happily. 1．The students in the US can go to the homework club ________. A．in the morning B．in the afternoon C．in the evening 2．The word “quiet” in Paragraph 1 means (意思是) ________. A．安静的 B．漂亮的 C．干净的 3．In the homework club, the students can’t ________. A．read books B．do their homework C．watch TV Passage 2 One day, on the way home from school, my mom told me she was going to make up some new rules for me and my brothers and sisters. Before this, we knew she wanted us to be good, but we really didn’t have any rules. Well, Mom took care of that. On Sunday, she started giving us some rules. Clean your rooms every other day. Be ready for dinner at 7:00 p.m. That means sitting at the table, Passage 1: 美国中学里的家庭作业俱乐部 Passage 2: 妈妈制定的新家规 Passage 3: 三种食物组之间的差异 Passage 4: Max热爱阅读的习惯 Passage 5: 有声阅读为什么如此受欢迎 Passage 6: 如何开始观鸟活动 Passage 7: 帮助融入新学校的方法 Passage 8: 植物感到压力时会发出声音 Passage 9: 作者最喜欢的地方——新泽西 Passage 10: 走路快慢和智力之间的关系 话题概览 原创精品资源学科网独家享有版权，侵权必究！ 2 with clean hands. If Mom is having a meeting in the house, be very quiet. That means turning down the music and the TV. Be ready for bed at 9:30 p.m. and get up at 7:30 a.m. to get ready for school. Take out the rubbish on Monday morning before school. Clean the bathroom on Thursday. Following these rules isn’t too hard, and sometimes it’s even fun. Other times, it can be tough. For example, if your room is really dirty and you can’t finish cleaning it on that day, you have to finish it on the next day, along with anything else you have to do. That isn’t easy. Mom made these rules because she loves us a lot. She wants us to learn how to be on time, be clean and neat, and be polite. Every day, we try to follow her rules. 4．What does the underlined word tough mean? A．Hard. B．Interesting. C．Easy. D．Boring. 5．What should the writer do on Monday? A．Have a class meeting. B．Take out the rubbish. C．Clean the bathroom. D．Take care of sisters. 6．What’s the best title of the passage? A．House rules. B．School rules. C．Family time. D．School life. Passage 3 Lots of kids want to keep healthy by eating well. Here’s something kids can do to eat healthily： learn the differences between Go, Slow and Whoa foods. The US National Heart, Lung and Blood Institute asks kids to start thinking about whether（是否）foods are Go foods, Slow foods or Whoa foods. Go foods These foods are good to eat almost anytime. They are the healthiest ones. Examples, tofu, fresh fruit (apples, oranges, bananas, etc.) and fresh vegetables (carrots, tomatoes, etc.). Slow foods We should eat these foods sometimes. We shouldn’t eat them every day. At says Susan. “I can’t 原创精品资源学科网独家享有版权，侵权必究！ 3 most, eat them a few times a week. Examples, 100% fruit juice, sports drinks and pancakes. Whoa foods These foods should make you say that—Whoa! Should I eat that? Whoa foods are least healthy. Examples：ice cream, cakes and candy. Now you know what Go, Slow and Whoa foods are. You can choose what to eat. Be sure to tell your parents about the three groups. Then everyone in the family can learn when to say Go and when to say Whoa! 7．The passage is written for ________. A．parents B．teachers C．kids D．cooks 8．Which of the following is Go food? A．Orange juice. B．Tofu. C．Ice cream. D．Candy. 9．What can we learn from the passage? A．We should eat Whoa foods every day. B．Children can have sports drinks anytime. C．Children should say “Whoa” to get ice cream. D．We can eat apple pancakes a few times a week. 10．What’s the passage mainly about? A．Some ideas about eating healthy food. B．Some ways of cooking food in the kitchen. C．The differences between three food groups. D．The interesting sayings about different foods. Passage 4 Max’s Good Habit (习惯) Max reads more than anyone he knows. He loves to read during all of his free time. His friends laugh at him because he would rather read than play video games, but his parents and his teachers are proud of him. They say reading is important, and it will help him learn about the world around him. One day Max was reading a magazine article (文章) about volcanoes. He told his friends all about volcanoes and what makes them erupt (喷发). The very next week, their teacher asked the class to do a science project about volcanoes. Guess who everyone wanted in their project group? Max’s friends 原创精品资源学科网独家享有版权，侵权必究！ 4 weren’t laughing at him anymore. Max ended up being in a group with Liz, Anna and Josh. The project was to make a poster board (展板) with information about volcanoes and to build a volcano model. Max made copies of the magazine article about volcanoes so his project partners could read about them too. They also went to the library to look for more information about volcanoes. The group met at Anna’s house that night to organize the information and decide what they wanted to put on the poster board. They all asked Max what he thought was most important. They made the decision together. The next night they met at Josh’s house to build their volcano. The volcano looked great. Max, Liz, Anna and Josh were very proud of their hard work. When they turned in their project, their teacher was proud too. Thanks to Max’s good habit, they got an A+ on both parts of the project. 11．What can we learn from the underlined sentence in Paragraph 2? A．Max was good at making friends. B．Other kids loved science very much. C．Max wanted to play games with others. D．Everyone wanted Max to join their group. 12．What did Max’s group do first? A．Asked their teacher for help. B．Made the poster board. C．Looked for information. D．Built the volcano model. 13．What is Max’s good habit? A．Reading books. B．Playing video games. C．Making models. D．Doing science projects. Passage 5 When we talk about reading, we probably think of eyes, because we read with our eyes. But we can do some reading with our ears, too. With the development (发展 ) of smart phones, it’s getting easier to do some reading with ears—by listening to stories, news, novels (小说) and so on. This is audio reading. Audio reading is becoming more and more popular these years. One of the reasons for this is that people can “read” in bed before going to sleep. Many people like to just stay in bed in the dark (黑暗) before they fall asleep. This would be the best time to do some audio reading. If you read a book made of paper, the lights have to be turned on (打开) and you have to turn the pages with your hand. But to do audio reading, you just stay in bed and ”read” with your ears. 原创精品资源学科网独家享有版权，侵权必究！ 5 People can do audio reading when the legs, body and arms are kept busy. For example, people can listen to audiobooks when they are exercising or doing housework. Some people would like to do audio reading in the kitchen. They think it’s boring to cook. So they can enjoy their time by listening to news or stories at the same time. Also, audio reading is helpful for blind (失明的) people. It’s difficult for them to read in the past. But now, with the help of audio reading, they can listen to what they want. Audio reading helps more people enjoy the fun of reading. Would you like to try audio reading? 14．What is audio reading? A．Reading with friends. B．Reading paper books. C．Reading at night. D．Reading by listening. 15．What can we learn about audio reading from the passage? A．Audio reading can make people read with no light. B．Audio reading helps people do more housework. C．Audio reading helps people cook nice food. D．Audio reading is difficult for blind people. 16．What is the passage mainly about? A．When to do audio reading. B．How to do audio reading well. C．Why audio reading is popular. D．What we need for audio reading. Passage 6 Let’s Go Birdwatching If you’re looking for a new hobby, birdwatching is a good choice (选择). A great thing about birdwatching is that anyone can do it. It’s an easy hobby. You can birdwatch on your own or with others. Birdwatching is also a relaxing hobby. Scientists say seeing and hearing birds can help people feel happy. Here is how to start birdwatching. Learn to Identify (识别) Birds To watch the birds, you have to get a bird book first. It will have all the information you need to identify different birds. It can help you learn about different families of birds, their habits and calls. You can also use an app. Merlin Bird ID is a free app. The app makes identifying birds easy and fun. It will let you identify birds by the sounds they make. 原创精品资源学科网独家享有版权，侵权必究！ 6 KnowWhere to Go Birdwatching You can watch the birds almost anywhere, including in your garden, yard, or just out of your window. If you live in the city, no problem! Head to the nearest park-especially during the spring and autumn when birds are on the move. Remember to visit places near water. Birds get thirsty. They like lakes and rivers. A lot of birds wake in the early morning hours because they’ve been nesting (筑巢) all night and want breakfast. So, start your birdwatching in the morning, when birds go out and look for food. Get Things You Need for Birdwatching Most of the time, you will hear bird calls from all around you, but they are far away in big trees. You can’t see them clearly. To watch these birds, you need binoculars. Binoculars can help you see birds up close. 17．Why does the writer think birdwatching is a good choice for hobbies? A．Because we can keep birds at home. B．Because it doesn’t need much money. C．Because we can travel far to find birds. D．Because it’s an easy hobby for everyone. 18．The word “binoculars” in Paragraph 6 probably means “________” in Chinese. A．录音笔 B．计时器 C．观鸟图册 D．望远镜 19．What can we learn from the passage? A．It’s not easy to go birdwatching in the city. B．Places near rivers are good places for birdwatching. C．A bird book tells us how to start birdwatching in a park. D．Merlin Bird ID can help identify birds by their pictures. 20．Which of the following would be the best heading (标题) for Paragraph 5? A．Keep a List of Birds B．Find a Special Bird C．Go at the Right Time D．Go with Other Watchers Passage 7 Moving to a new school can be difficult. Here are some tips to help you to fit in (融入). Take a day to know your school. You won’t fit in at school if you don’t know the school well. Ask for a school map. Try to get to know every corner of your new school. A good school handbook can be of great help. But to make it 原创精品资源学科网独家享有版权，侵权必究！ 7 easy, ask the people near you where something is—tell people that you are new when you need help. Be nice to everyone. Be nice to everyone, the young or the old, because they might just be your next teacher or friend. Make friends. Talk to different people. This is your school now. Take a chance (机会) on being who you weren’t at your old school. Join a few clubs or sports teams and make more friends in this way. Be yourself and be polite. Don’t worry too much about what people think of you. Be true, be yourself, and be nice to everyone. It’s often the girl or the boy that you didn’t like at your new school that ends up (最终 ) being your friend after a little while. But then again, stand up for yourself if it’s very clear that you should. Work hard to fit in while still being yourself. The first few weeks are always hard, but you’ll soon get used to it. 21．Which of the following is easy to know your new school in a day? A．Reading a handbook. B．Walking around the school. C．Asking people for help. D．Looking at a map quickly. 22．The words “stand up for yourself” in Paragraph 5 mean “________”. A．try to stand up B．be not friendly C．do things by yourself D．do not change your idea 23．What’s the best title for the passage? A．How to Know a New School B．How to Fit in at a New School C．How to Be Yourself at School D．How to Make Friends at School Passage 8 Plants Crying in Pain 原创精品资源学科网独家享有版权，侵权必究！ 8 Try to think about this: you sit down and begin to eat a tomato. Suddenly, the tomato starts to scream (尖叫)! This would never really happen. But a new study shows that plants make sounds when they are stressed. Scientists in Israel did the study. They used ultrasonic microphones to record (记录) the sounds of tomato plants in boxes. They listened to three groups of plants. The first two groups made sounds 30 to 50 times every hour. The third group only made the sound once every hour. “When tomatoes are not stressed at all, they are very quiet (安静的),” Lilach Hadany from the study team told CNN. Scientists believed that animals and insects may listen to the sounds. For example, the sound can tell them that the plant is stressed and not good for laying eggs (产卵) on. When an animal wants to eat plants, it can also use sound to choose which one to eat. The scientists also listened to other crops such as wheat (小麦) and corn. They also made more sounds when stressed. Scientists said the study can help farmers in the future. They can better take care of the crops by “hearing” how plants feel. 24．The third paragraph is mainly about ________. A．what the new study found B．where the sound comes from C．why scientists made the study D．how tomatoes find the sound 25．According to the scientists, by hearing the sounds, animals can ________. A．feel as stressed as the plants B．know when to help the plants rest C．find out the best plants to use or eat D．protect themselves from dangerous plants 26．The study may help the farmers ________ in the future. 原创精品资源学科网独家享有版权，侵权必究！ 9 A．look after the crops better B．stay safe while planting C．talk to their crops easily D．get more wheat than corn 27．What can we learn from the passage? A．Crops may grow better when we touch them often. B．Farmers may eat more tomatoes after learning about the sound. C．Scientists may study the sound better after watching the plants. D．Tomatoes may make more sounds when we cut off their stems. Passage 9 Do you have a favorite place to go—a place with family, good weather, and fun things to do like crabbing (抓螃蟹)? I’m glad I do. New Jersey is my favorite place for many reasons. The first reason is my family. Over half of my family lives in New Jersey. When I visit, my cousins and I laugh and play all day and night. My uncles and aunts take me to the boardwalk where we ride roller coasters (过山车). We try juicy apples and foot-long hot dogs. My family is fun to be with. The second reason for New Jersey being my favorite place is the weather. Instead of being hot, it’s always cool. When I think about my visits, I can just feel the cool autumn wind in my hair. I can just see the white, soft winter snow. I can just hear the soft spring rain splashing on the sidewalks. I can just feel the warm summer sun on my face. The weather is great! The third reason for New Jersey being my favorite place is crabbing. If it’s crab season, we crab. We keep the blue crabs and the snow crabs, and we let the others go. Sometimes we catch crabs on hooks (钩子), and sometimes we lower crab cages (笼子) into the water. Then we pull them out later. One time my brother caught a crab so big that it got stuck in the crab cage!The crab finally got out, but it hurt one of its legs and broke the cage. Poor crab! For all these reasons, New Jersey is my favorite place to go. If you don’t have a favorite place, I think you should search for one. It’s good to visit a favorite place—a place where you can make special memories. 28．What can we know about the writer? A．All his family members live in the same place. 原创精品资源学科网独家享有版权，侵权必究！ 10 B．He has lots of fun staying with his cousins. C．His uncles and aunts are very busy. D．New Jersey is his hometown. 29．What’s the weather like in New Jersey? A．It rains a lot in spring. B．It has heavy snow in winter. C．It’s hot in summer and cold in winter. D．It’s warm in summer and cool in autumn. 30．When the writer catches crabs, he ________. A．lets some crabs go B．likes using crab cages C．puts the crabs on hooks D．keeps the biggest crabs 31．What’s the passage mainly about? A．Famous things in New Jersey. B．Wonderful places in New Jersey. C．Why the writer likes New Jersey. D．How the writer goes to New Jersey. Passage 10 Do you walk slowly? If so, you may not want to hear the findings of this study. Scientists at Duke University found that the slower a person walks, the less（较少的）capable his or her brain is. Scientists studied the walking speeds（速度）of 904 middle—aged people from New Zealand starting from when they were just 3 years old. Over 42 years, scientists tested their walking speed many times. They found that the speed had something to do with the brain. If the subjects （实验对象）had lower IQ scores and worse language skills as children, they were likely to become slow walkers as they reached middle age. At the age of 45, the average gap in IQ between the slowest and the fastest walkers was 16 points. Scientists said that genes （基因） might be the reason for this. However, smarter people may be 原创精品资源学科网独家享有版权，侵权必究！ 11 more likely to do physical activity, which means they may walk faster later in life. Can slower walkers make their brains work better? Maybe. Scientists looked at the brain scans of 926 people. They asked them to walk as fast as they can for two minutes. Scientists checked the distance they walked and then asked them to take some tests. Those who walked further and faster did better on the tests. 32．Scientists found that people who walk slowly ________. A．are much smarter B．are good at working C．may be less smart D．have high IQ scores 33．What do we know about the study? A．Most people in the study were 42 years old. B．People in the study were smarter than other people. C．Scientists at Duke University studied 1, 000 people. D．Scientists tested people’s walking speed more than once. 34．What’s the main idea of paragraph 4? A．The ages of the subjects. B．The findings of the study. C．How to get better skills. D．How to carry out the study. 原创精品资源学科网独家享有版权，侵权必究！ 1 专项 4 阅读理解-说明文 答案解析 快速对答案： 题号 1 2 3 4 5 6 7 8 9 10 答案 B A C A B A C B C C 题号 11 12 13 14 15 16 17 18 19 20 答案 D C A D A C D D B C 题号 21 22 23 24 25 26 27 28 29 30 答案 C D B A C A D B D A 题号 31 32 33 34 答案 C C D B 答案解析： Passage 1 1．B 2．A 3．C 【导语】本文主要介绍了美国中学里的家庭作业俱乐部。 1．细节理解题。根据“More and more students spend (度过) their afternoons in the homework club.” 可知，家庭作业俱乐部的时间是下午，故选 B。 2．词句猜测题。根据“The US middle school students need a quiet place to study. But games, computers and TVs are all around kids at home.”可知，在家里，游戏、电脑和电视充斥着孩子们， 所以家庭作业俱乐部是安静的，故选 A。 3．细节理解题。根据“So the homework club is just for them to do their homework. The club is quiet and it’s also good for students to read their favorite books.”可知，在庭作业俱乐部可以做作业和看 书，故选 C。 Passage 2 4．A 5．B 6．A 【导语】本文主要讲述作者的妈妈制定的新家规。 4．词义猜测题。根据“if your room is really dirty and you can’t finish cleaning it on that day, you have to finish it on the next day, along with anything else you have to do. That isn’t easy.”可知如果你的房 间真的很脏，而你当天又打扫不完，你就必须在第二天把它打扫完，还要做其他的事情，这并 不容易，可见遵守这些规则很难。故选 A。 5．细节理解题。根据“Take out the rubbish on Monday morning before school”可知作者在星期一 要倒垃圾。故选 B。 原创精品资源学科网独家享有版权，侵权必究！ 2 6．最佳标题题。本文主要讲述作者的妈妈制定的新家规，以选项 A“家规”为标题最合适。故选 A。 Passage 3 7．C 8．B 9．C 10．C 【导语】本文主要讲述了三种食物组之间的差异。 7．推理判断题。根据“Here’s something kids can do to eat healthily：learn the differences between Go, Slow and Whoa foods.”可知，这篇文章是为孩子们写的。故选 C。 8．细节理解题。根据“Go foods——These foods are good to eat almost anytime. They are the healthiest ones. Examples, tofu, fresh fruit (apples, oranges, bananas, etc.) and fresh vegetables (carrots, tomatoes, etc.).”可知，四个选项中豆腐是 Go食物。故选 B。 9．推理判断题。根据“Should I eat that? Whoa foods are least healthy. Examples：ice cream, cakes and candy.”可知，我们能从这篇文章中学到：孩子们应该说“Whoa”，来吃冰淇淋。故选 C。 10．主旨大意题。根据“Here’s something kids can do to eat healthily：learn the differences between Go, Slow and Whoa foods.”以及结合全文可知，文章主要介绍了三种食物组之间的差异。故选 C。 Passage 4 11．D 12．C 13．A 【导语】本文讲述了Max热爱阅读的习惯帮助他和他的组员在班级课题研究中获得高分的事情。 11．推理判断题。根据“One day Max was reading a magazine article (文章) about volcanoes.”可知， Max通过阅读了解一些与火山相关的知识；再根据“The very next week, their teacher asked the class to do a science project about volcanoes.”可知，老师让他们做一个与火山相关的项目；结合 Max的知识储备，推知很多同学想和Max一组。故选 D。 12．细节理解题。根据“They also went to the library to look for more information about volcanoes.” 可知，Max所在的组做的第一件事是去图书馆查找信息。故选 C。 13．推理判断题。根据“He loves to read during all of his free time.”和“Thanks to Max’s good habit, they got an A+ on both parts of the project.”可推知，Max的好习惯是读书。 Passage 5 14．D 15．A 16．C 【导语】本文主要介绍了有声阅读为什么如此受欢迎。 14．细节理解题。根据“With the development (发展) of smart phones, it’s getting easier to do some reading with ears—by listening to stories, news, novels (小说) and so on. This is audio reading.”可知 有声阅读是通过听来读书。故选 D。 15．推理判断题。根据“Many people like to just stay in bed in the dark (黑暗) before they fall asleep. This would be the best time to do some audio reading”可知许多人喜欢在天黑前躺在床上睡觉，这 原创精品资源学科网独家享有版权，侵权必究！ 3 将是进行音频阅读的最佳时机，可推知有声阅读可以让人在没有灯光的情况下阅读。故选 A。 16．主旨大意题。本文主要介绍了有声阅读为什么如此受欢迎。故选 C。 Passage 6 17．D 18．D 19．B 20．C 【导语】本文主要介绍了如何开始观鸟活动。 17．细节理解题。根据“A great thing about birdwatching is that anyone can do it. It’s an easy hobby.” 可知因为这是一个容易的爱好。故选 D。 18．词义猜测题。根据“To watch these birds, you need binoculars. Binoculars can help you see birds up close.”可知可以帮助你近距离观察鸟类的是望远镜。故选 D。 19．细节理解题。根据“Remember to visit places near water. Birds get thirsty. They like lakes and rivers.”可知记得去靠近水的地方，鸟喜欢湖泊和河流，所以靠近河流的地方是观鸟的好地方。 故选 B。 20．最佳标题题。根据“So, start your birdwatching in the morning, when birds go out and look for food.”可知此处介绍去观鸟的时间，选项 C“在合适的时间去”符合。故选 C。 Passage 7 21．C 22．D 23．B 【导语】本文主要向我们介绍了帮助融入新学校的方法。 21．细节理解题。根据“But to make it easy, ask the people near you where something is—tell people that you are new when you need help.”可知，向他人寻求帮助是你了解新学校的简便方式。故选 C。 22．词句猜测题。根据“Don’t worry too much about what people think of you. Be true, be yourself, and be nice to everyone. ... But then again, stand up for yourself if it’s very clear that you should.”可 知，不要太在意别人对你的看法，做真实的自己，所以划线此句应是表示“不要改变你的想法”， 故选 D。 23．最佳标题题。本文主要向我们介绍了帮助融入新学校的方法，选项 B“如何适应新学校”符 合主题，故选 B。 Passage 8 24．A 25．C 26．A 27．D 【导语】本文是一篇说明文，介绍了一项新的研究，即植物在感到压力时会发出声音。 24．段落大意题。分析第三段内容可知，本段主要介绍该项研究的发现，故选 A。 25．细节理解题。根据“Scientists believed that animals and insects may listen to the sounds. For example, the sound can tell them that the plant is stressed and not good for laying eggs (产卵) on. When an animal wants to eat plants, it can also use sound to choose which one to eat.”可知，这种声音 可以告诉动物们，植物受到了压力，不适合产卵。当动物想要吃植物时，它也可以用声音来选 原创精品资源学科网独家享有版权，侵权必究！ 4 择吃哪一种。所以通过听到声音，动物可找出最适合使用或食用的植物。故选 C。 26．细节理解题。根据“Scientists said the study can help farmers in the future. They can better take care of the crops by ‘hearing’ how plants feel.”可知，这项研究可以在未来帮助农民。他们可以通 过“倾听”植物的感受来更好地照顾作物。故选 A。 27．推理判断题。根据“When tomatoes are not stressed at all, they are very quiet (安静的)”可知， 当番茄完全没有压力时，它们非常安静，由此推知，当我们切断番茄的茎时，它可能会发出更 多的声音。故选 D。 Passage 9 28．B 29．D 30．A 31．C 【导语】本文介绍了作者最喜欢的地方——新泽西，以及他喜欢新泽西的三个原因。 28．细节理解题。根据“Over half of my family lives in New Jersey. When I visit，my cousins and I laugh and play all day and night.”可知，我和堂兄弟玩得很开心。故选 B。 29．细节理解题。根据“I can just feel the cool autumn wind”以及“I can just feel the warm summer sun.”可知，新泽西的天气是夏天温暖，秋天凉爽。故选 D。 30．细节理解题。根据“We keep the blue crabs and the snow crabs, and we let the others go.”可知， 作者抓螃蟹时会放走其中一些。故选 A。 31．主旨大意题。根据“New Jersey is my favorite place for many reasons.”以及文中列举的三个原 因可知，本文主要讲述作者喜欢新泽西的原因。故选 C。 Passage 10 32．C 33．D 34．B 【导语】本文讲述了走路快慢和智力之间的关系。 32．细节理解题。根据“Scientists at Duke University found that the slower a person walks, the less （较少的）capable his or her brain is.”可知，科学家们发现，走路慢的人可能不那么聪明。故选 C。 33．推理判断题。根据“Over 42 years, scientists tested their walking speed many times.”可知，学家 们不止一次测试了人们的行走速度。故选 D。 34．主旨大意题。根据“They found that the speed had something to do with the brain. If the subjects （实验对象）had lower IQ scores and worse language skills as children, they were likely to become slow walkers as they reached middle age. At the age of 45, the average gap in IQ between the slowest and the fastest walkers was 16 points.”可知，本文主要讲述了这项研究的发现。故选 B。