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（北京专用）英语八年级（上）期末真题分项汇总
C
Later School Start Helps Kids Get Zzz
Teenagers have been sleeping less. This is an issue all across the United States. Research from Harvard Medical School shows that having less sleep can make teens fat and cause some developmental problems. Because of the increasing use of devices like smartphones and computers, students today are staying up late. Many teens use them long after dark. “At night, I am on my phone and I just want to stay up. I often wake up so tired that I wish I could go back to sleep,” Hazel Ostrowski, a high school student, said.
To make matters worse, 93% of high schools and 83% of middle schools in the U.S. start before 8:30 a. m. That time goes against official health advice from American Academy of Pediatrics (美国儿科学会). Schools do not want late start times, because it will cause traffic problems. Parents also want older kids to come home early to watch younger kids in the afternoons.
But some studies suggest that students between the ages of 11 and 17 get enough sleep on school nights. Therefore, some researchers suggest starting school late.
Researchers are studying later school start times in Seattle, Washington. The Seattle School District (区) made a big time change in the fall of 2016. The change was for high schools and most middle schools. Before, the first bell rang at 7:50 a. m. After the change, classes began at 8:45 a. m.
The researchers worked with science teachers at two high schools in Seattle, and 178 teenagers took part in the study. They wore activity monitors to discover whether a later start to the school day would help them get more sleep. The researchers compared sleep habits (习惯) of these teens in spring 2016，before the change, to sleep habits of them from spring 2017, after later start times began.
What changed was wake-up time. Morning wake-up time changed from 6:24 a. m. to 7:08 a. m. Falling asleep changed only a bit. It went from 11 :27p. m. to 11:38 p. m.
Researchers noticed that there were fewer late students after the changes. The study also found the students got about 34 more minutes of sleep each night. Students also felt less sleepy in the daytime. Their grades improved as well. It seems a later start to school is helping students.
27. In the first paragraph, the writer gives the example of Hazel to show________.
A. students wake up tired from sleeping too long
B. students want to stay up late to have a good time
C. students become much fatter for taking less exercise
D. students sleep less because of using smartphones long
28. According to the study, the Seattle School District ________.
A. starts school at 8:30 in the morning B. starts school 55 minutes later than usual
C. asks students to change their sleeping habits D. asks parents to make sure their kids go to bed early
29. What is the last paragraph mainly about
A. Reasons for later school start. B. Advantages of later school start.
C. Causes of less sleep in students. D. Solutions to the problem of sleeping less.
C
Growing up in the Chinese community in Vancouver, Canada, I had full time to experience both Canadian and Chinese culture during my childhood.
In my community, many traditions and cultural traits brought by Chinese immigrants（移民）remain alive. For example, interactions (互动) between Chinese neighbors: People greet each other warmly and sometimes stop for a chat. Families also stay mostly the same after crossing the ocean. Elderly members still live with their children instead of in care homes.
Another similarity is that many of us celebrate traditional Chinese holidays, such as Spring festival. Although it's in a different country, the holidays are still commemorated with the same foods, entertainment ( 娱乐活动 ) and values as they are in China. My family makes sure to watch the Spring Festival Gala each year, for example.
While many ways of Chinese culture truly remain in Vancouver, there are also certain ways that the Chinese and Canadian cultures have mixed to create something new and special. Many children of Chinese immigrants, like myself, study in English at school and speak Chinese at home, leading to communication without any trouble in both languages. Chinese communities also celebrate Canadian holidays, like Halloween, which are not often celebrated in China.
Canadian culture has even taken on some Chinese foods and language. Chinese dishes are very popular throughout Canada, many people are very interested in trying them. More and more non-Chinese Canadians are learning the language in order to enjoy Chinese holiday celebrations and communicate with their Chinese of the same age.
As someone who grew up Chinese Canadian, I'm very proud of my special background and how it has made me the person I am today.
27. According to the passage, what are Chinese immigrants in the writer's community like
A. They seem too busy to stop for a chat.
B. Elderly people prefer to stay in care homes.
C. They also remain many Chinese traditions and values.
D. Their lifestyles remain unchanged after moving to Canada.
28. What does the underlined word commemorated probably mean
A. made. B. started. C. described. D. celebrated.
29. What can we infer from the passage
A. Canadians are open to Chinese culture.
B. Many Canadians can't get well with Chinese immigrants.
C. Canadians usually do better than Chinese people at school.
D. Canadians are unhappy with the influence of Chinese culture.
Working on Your Workout
Most people know that regular (经常的) exercise is very important for good health and appearance. However, most people do not know how to exercise in the right way. They make the same common workout mistakes. If someone is not working out correctly, he or she will hardly see the results he or she wants. Here are a few tips to help you get the best workout results.
One of the most common workout mistakes is doing the same routine (日常锻炼) over and over again. This does not challenge your muscles (肌肉), and it can actually stop your muscles from growing and repairing themselves. It is important to change your routine every six to eight weeks. You can add different workouts to your routine, such as swimming, yoga or biking, to make sure your whole body stays fit. This will help make your workouts more interesting, and benefit your health and muscle development as well.
Another mistake people often make is to work out too hard, too often. Your body needs to rest between workouts. It is best to have no more than two hard workouts every week. If you want to have more than two hard workouts every week, you’d better work out for only about twenty minutes on the other days. Or you can plan easier workouts for forty to sixty minutes between days of shorter and harder workouts. However, experts suggest resting at least one day each week, especially after hard workout days.
If you want to make a real difference in your health, remember not to make these common workout mistakes, and always have fun while exercising.
28. Changing your workout routine every six to eight weeks can ________.
A. make workouts easier for you
B. help your whole body stay fit
C. stop your muscles from growing
D. make you lose interest in working out
29. What suggestion does the passage give us
A. Resting at least one day every week.
B. Doing hard workouts for an hour every day.
C. Having more than two hard workouts every week.
D. Planning easy workouts before hard workouts every time.
30. What’s the main idea of this passage
A. We should try to have fun while exercising.
B. Regular exercise is very important for good health.
C. Most people know how to exercise in the right way.
D. Exercising correctly is the key to getting the best results.
C
Nowadays, some schools teach traditional subjects like math, geography, and language, but they also teach life skills(技能). Life skills classes teach students how to keep their rooms clean and tidy, take care of their health, and have healthy personal relationships(关系). Some people say these classes prepare students better for life in the real world. But other people say these classes aren’t important. Students should only pay attention to how to get into university. What do you think
Some people like the idea of teaching life skills in schools. They believe that life skills classes give students what they need to know to live on their own, whether they go to college or get a job after high school. They help prepare students for everyday real-life situations, such as cooking a meal and managing money. Many of these classes also teach “soft skills”, like how to listen and talk to people in a positive(积极的) way, which are important in the workplace and in personal relationships. As students learn more life skills, they become more confident in themselves.
On the other hand, some people argue that there is no time for more subjects at school. They think it’s more important to teach traditional subjects than life skills at school. Many students choose not to take life skills classes because these classes don’t improve their chances of getting into university. People also think it should be the job of parents to teach their kids what they need to know at home.
Personally, I think we already learn many life skills while doing traditional subjects. For example, we learn teamwork by doing group work, and organizing(安排) our homework teaches us how to use our time well. I believe all schools should teach life skills. It would not need too much work because there is no need to teach them separately(分开地) from traditional subjects. This will make sure that students are better prepared for college and work when they leave school.
27. What is Paragraph 2 mainly about
A. The different ways to live on your own.
B. The school experience of learning life skills.
C. The situation that calls for learning life skills.
D. The advantages of learning life skills in school.
28. The writer probably agrees that ________.
A. schools need to give more time to life skills classes
B parents’ first job is to teach their children life skills
C. students can learn life skills in their traditional subjects
D. teachers should learn life skills together with their students
29. What might be the best title for the passage
A. Life Skills: How Do Students Build Them
B. Life Skills: Should School Teach Them
C. Life Skills: Who Should Learn Them
D. Life Skills: Are They Important
C
Polar Bears Could Die Out by the End of the Century
The heating of Earth is pushing the number of polar bears to get smaller and smaller. According to a new study, they could die out in fewer than 100 years.
Polar bears are animals which live by eating sea seals in the Arctic Ocean. As more and more sea ice melts (融化), their living places become to shrink. The loss (丧失) of sea ice began to be paid more attention at the end of the 1970s. Since then, sea ice that lasts for more than a year in the Arctic has decreased at a rate of 13% per decade.
Studies have long shown that the growing loss of sea ice will lead to a dangerous situation for polar bears, but the new research shown in Nature Climate Change has given us a clear dying out timeline. Polar bears will be unable to live because of the climate (气候) change over the next several decades (十年). The scientists believe they will completely die out by 2100.
“What we’ve found out is that, first, it will be very difficult for cubs (幼崽) to be born and live. Even if cubs are born, the mother polar bears won’t have enough body fat (脂肪) to produce milk to bring them along through the ice-free season.” said Dr. Steven Amstrup, a scientist of Polar Bears International, to the BBC. “Any of us knows that we can’t go without food for a long time. That’s a natural need for all humans and animals.”
The research also shows that, even in a situation where many countries have done a lot of work to save polar bears, several populations (族群) of polar bears will die out. But Amstrup strongly believes that the animals can still do whatever they can do to live if the climate change does not go on getting worse.
“We must show how dangerous the situation is, because we have to do something now to stop the worst of future problems.” He said. “The way we’re on now is not good enough, but if society can do something together, we will have time to save polar bears. And if we do, we will do great good to other lives on Earth, and to ourselves too.”
27 The word “shrink” in Paragraph 2 probably means “__________”.
A. get bigger B. get lighter C. get smaller D. get heavier
28. According to the passage, polar bears will probably die out because _________.
A. sea seals in the Arctic Ocean don’t have enough body fat
B. sea ice becomes less because of the climate change
C. the new research has given a dying out timeline
D. fewer animal scientists pay attention to them
29. What is Paragraph 4 mainly about
A. Why cubs are hard to be born and live in ice-free season.
B. Why humans and animals can’t live through without food.
C. Why mother polar bears can’t produce enough milk for cubs.
D. Why Dr. Steven Amstrup does the research about polar bears.（北京专用）英语八年级（上）期末真题分项汇总
C
Later School Start Helps Kids Get Zzz
Teenagers have been sleeping less. This is an issue all across the United States. Research from Harvard Medical School shows that having less sleep can make teens fat and cause some developmental problems. Because of the increasing use of devices like smartphones and computers, students today are staying up late. Many teens use them long after dark. “At night, I am on my phone and I just want to stay up. I often wake up so tired that I wish I could go back to sleep,” Hazel Ostrowski, a high school student, said.
To make matters worse, 93% of high schools and 83% of middle schools in the U.S. start before 8:30 a. m. That time goes against official health advice from American Academy of Pediatrics (美国儿科学会). Schools do not want late start times, because it will cause traffic problems. Parents also want older kids to come home early to watch younger kids in the afternoons.
But some studies suggest that students between the ages of 11 and 17 get enough sleep on school nights. Therefore, some researchers suggest starting school late.
Researchers are studying later school start times in Seattle, Washington. The Seattle School District (区) made a big time change in the fall of 2016. The change was for high schools and most middle schools. Before, the first bell rang at 7:50 a. m. After the change, classes began at 8:45 a. m.
The researchers worked with science teachers at two high schools in Seattle, and 178 teenagers took part in the study. They wore activity monitors to discover whether a later start to the school day would help them get more sleep. The researchers compared sleep habits (习惯) of these teens in spring 2016，before the change, to sleep habits of them from spring 2017, after later start times began.
What changed was wake-up time. Morning wake-up time changed from 6:24 a. m. to 7:08 a. m. Falling asleep changed only a bit. It went from 11 :27p. m. to 11:38 p. m.
Researchers noticed that there were fewer late students after the changes. The study also found the students got about 34 more minutes of sleep each night. Students also felt less sleepy in the daytime. Their grades improved as well. It seems a later start to school is helping students.
27. In the first paragraph, the writer gives the example of Hazel to show________.
A. students wake up tired from sleeping too long
B. students want to stay up late to have a good time
C. students become much fatter for taking less exercise
D. students sleep less because of using smartphones long
28. According to the study, the Seattle School District ________.
A. starts school at 8:30 in the morning B. starts school 55 minutes later than usual
C. asks students to change their sleeping habits D. asks parents to make sure their kids go to bed early
29. What is the last paragraph mainly about
A. Reasons for later school start. B. Advantages of later school start.
C. Causes of less sleep in students. D. Solutions to the problem of sleeping less.
【答案】27. D 28. B 29. B
【解析】
【分析】本文是一篇说明文，介绍了美国某些地区推迟学校早晨的上课时间，为了让青少年有更多的睡眠时间，效果显著。
【27题详解】
细节理解题。根据例子之前的“Because of the increasing use of devices like smartphones and computers，students today are staying up late. Many teens use them long after dark”，可知此处举例是为了说明学生们因为使用手机所以睡眠时间更少了，故选D。
【28题详解】
细节理解题。根据“The Seattle School District made a big time change in the fall of 2016…Before, the first bell rang at 7:50 a. m. After the change, classes began at 8:45 a. m.”，可知西雅图早晨上课时间由之前的早上七点五十推迟到了早上八点四十五，比以往推迟了55分钟，故选B。
【29题详解】
段落主旨题。通读整段，可知该段主要介绍了学校早晨推迟上学的好处，包括“迟到的学生变少了，学生睡眠时间延长了，学生成绩改善了”，故选B。
C
Growing up in the Chinese community in Vancouver, Canada, I had full time to experience both Canadian and Chinese culture during my childhood.
In my community, many traditions and cultural traits brought by Chinese immigrants（移民）remain alive. For example, interactions (互动) between Chinese neighbors: People greet each other warmly and sometimes stop for a chat. Families also stay mostly the same after crossing the ocean. Elderly members still live with their children instead of in care homes.
Another similarity is that many of us celebrate traditional Chinese holidays, such as Spring festival. Although it's in a different country, the holidays are still commemorated with the same foods, entertainment ( 娱乐活动 ) and values as they are in China. My family makes sure to watch the Spring Festival Gala each year, for example.
While many ways of Chinese culture truly remain in Vancouver, there are also certain ways that the Chinese and Canadian cultures have mixed to create something new and special. Many children of Chinese immigrants, like myself, study in English at school and speak Chinese at home, leading to communication without any trouble in both languages. Chinese communities also celebrate Canadian holidays, like Halloween, which are not often celebrated in China.
Canadian culture has even taken on some Chinese foods and language. Chinese dishes are very popular throughout Canada, many people are very interested in trying them. More and more non-Chinese Canadians are learning the language in order to enjoy Chinese holiday celebrations and communicate with their Chinese of the same age.
As someone who grew up Chinese Canadian, I'm very proud of my special background and how it has made me the person I am today.
27. According to the passage, what are Chinese immigrants in the writer's community like
A. They seem too busy to stop for a chat.
B. Elderly people prefer to stay in care homes.
C. They also remain many Chinese traditions and values.
D. Their lifestyles remain unchanged after moving to Canada.
28. What does the underlined word commemorated probably mean
A. made. B. started. C. described. D. celebrated.
29. What can we infer from the passage
A. Canadians are open to Chinese culture.
B. Many Canadians can't get well with Chinese immigrants.
C. Canadians usually do better than Chinese people at school.
D. Canadians are unhappy with the influence of Chinese culture.
【答案】27. C 28. D 29. A
【解析】
【分析】文章大意：文章讲的是中国移民到加拿大带的许多传统和文化依然存在，使中国文化融入到了加拿大。
【27题详解】
细节理解题。根据文章第二段第一、二行In my community, many traditions and cultural traits brought by Chinese immigrants（移民）remain alive“在我的社区里，中国移民带来的许多传统和文化特征依然存在”，故选C。
【28题详解】
词句猜测题。根据文章第三段第二行划线单词前面的the holidays“节日”和后面的with the same foods“用同样的食物”可推知commemorated是庆祝的意思，made制作；started开始；described描述；celebrated庆祝，故选D。
【29题详解】
推测题。根据文章倒数第二段第一行Canadian culture has even taken on some Chinese foods and language“加拿大文化甚至还带有一些中国食物和语言。”可知，A说法是正确的；根据文章第二段第二、三行People greet each other warmly and sometimes stop for a chat.“人们互相热情地打招呼，有时停下来聊聊天。”可知， B说法是错误的；根据文章第二段第二、三、四行Many children ……Canadian holidays“许多中国移民的孩子，像我一样，在学校学英语，在家里说汉语，导致两种语言的交流没有任何困难。”可知C说法是错误的；根据倒数第二段第二、三、四行More and more non-Chinese Canadians are …… the same age“越来越多的非华裔加拿大人为了享受中国的节日庆典，与同龄华人交流，正在学习这门语言。”可知，D说法是错误的，故选A。
【点睛】阅读理解题中的细节理解题，首先找出问句中的关键词，然后定位到文章具体位置，然后选出正确答案即可。
例如题目1中，关键词是Chinese immigrants in the writer's community，可定位到文章第二段第一、二行In my community, many traditions and cultural traits brought by Chinese immigrants（移民）remain alive“在我的社区里，中国移民带来的许多传统和文化特征依然存在”，故选C。
Working on Your Workout
Most people know that regular (经常的) exercise is very important for good health and appearance. However, most people do not know how to exercise in the right way. They make the same common workout mistakes. If someone is not working out correctly, he or she will hardly see the results he or she wants. Here are a few tips to help you get the best workout results.
One of the most common workout mistakes is doing the same routine (日常锻炼) over and over again. This does not challenge your muscles (肌肉), and it can actually stop your muscles from growing and repairing themselves. It is important to change your routine every six to eight weeks. You can add different workouts to your routine, such as swimming, yoga or biking, to make sure your whole body stays fit. This will help make your workouts more interesting, and benefit your health and muscle development as well.
Another mistake people often make is to work out too hard, too often. Your body needs to rest between workouts. It is best to have no more than two hard workouts every week. If you want to have more than two hard workouts every week, you’d better work out for only about twenty minutes on the other days. Or you can plan easier workouts for forty to sixty minutes between days of shorter and harder workouts. However, experts suggest resting at least one day each week, especially after hard workout days.
If you want to make a real difference in your health, remember not to make these common workout mistakes, and always have fun while exercising.
28. Changing your workout routine every six to eight weeks can ________.
A. make workouts easier for you
B. help your whole body stay fit
C. stop your muscles from growing
D. make you lose interest in working out
29. What suggestion does the passage give us
A. Resting at least one day every week.
B. Doing hard workouts for an hour every day.
C. Having more than two hard workouts every week.
D. Planning easy workouts before hard workouts every time.
30. What’s the main idea of this passage
A. We should try to have fun while exercising.
B. Regular exercise is very important for good health.
C. Most people know how to exercise in the right way.
D. Exercising correctly is the key to getting the best results.
【答案】28. B 29. A 30. D
【解析】
【导语】本文介绍一些锻炼技巧以帮助人们获得最佳锻炼效果。
【28题详解】
细节理解题。根据第一段“It is important to change your routine every six to eight weeks…This will help make your workouts more interesting, and benefit your health and muscle development as well.”可知，每六到八周改变一次锻炼可以确保整个身体保持健康。故选B。
【29题详解】
推理判断题。根据第三段“However, experts suggest resting at least one day each week, especially after hard workout days.”专家建议每周至少休息一天，尤其是在艰苦的训练日之后；可知，选项A“每周至少休息一天”表述正确。故选A。
【30题详解】
主旨大意题。本文介绍一些锻炼技巧以帮助人们获得最佳锻炼效果；可知选项D“正确的锻炼是获得最佳结果的关键”符合文意。故选D。
C
Nowadays, some schools teach traditional subjects like math, geography, and language, but they also teach life skills(技能). Life skills classes teach students how to keep their rooms clean and tidy, take care of their health, and have healthy personal relationships(关系). Some people say these classes prepare students better for life in the real world. But other people say these classes aren’t important. Students should only pay attention to how to get into university. What do you think
Some people like the idea of teaching life skills in schools. They believe that life skills classes give students what they need to know to live on their own, whether they go to college or get a job after high school. They help prepare students for everyday real-life situations, such as cooking a meal and managing money. Many of these classes also teach “soft skills”, like how to listen and talk to people in a positive(积极的) way, which are important in the workplace and in personal relationships. As students learn more life skills, they become more confident in themselves.
On the other hand, some people argue that there is no time for more subjects at school. They think it’s more important to teach traditional subjects than life skills at school. Many students choose not to take life skills classes because these classes don’t improve their chances of getting into university. People also think it should be the job of parents to teach their kids what they need to know at home.
Personally, I think we already learn many life skills while doing traditional subjects. For example, we learn teamwork by doing group work, and organizing(安排) our homework teaches us how to use our time well. I believe all schools should teach life skills. It would not need too much work because there is no need to teach them separately(分开地) from traditional subjects. This will make sure that students are better prepared for college and work when they leave school.
27. What is Paragraph 2 mainly about
A. The different ways to live on your own.
B. The school experience of learning life skills.
C. The situation that calls for learning life skills.
D. The advantages of learning life skills in school.
28. The writer probably agrees that ________.
A. schools need to give more time to life skills classes
B parents’ first job is to teach their children life skills
C. students can learn life skills in their traditional subjects
D. teachers should learn life skills together with their students
29. What might be the best title for the passage
A. Life Skills: How Do Students Build Them
B. Life Skills: Should School Teach Them
C. Life Skills: Who Should Learn Them
D. Life Skills: Are They Important
【答案】27. D 28. C 29. B
【解析】
【导语】本文介绍了是否应该教授生活技能课。
【27题详解】
主旨大意题。根据第二段“Some people like the idea of teaching life skills in schools. They believe that life skills classes give students what they need to know to live on their own…As students learn more life skills, they become more confident in themselves.”可知，学习生活技能能让学生为日常生活做好准备，能让他们学到很多“软技能”等等，因此本段讲述的是在学校学习生活技能的优势。故选D。
【28题详解】
细节理解题。根据“Personally, I think we already learn many life skills while doing traditional subjects.”可知，作者认为学生可以在传统课程中学习生活技能。故选C。
【29题详解】
最佳标题题。根据文章内容可知，本文介绍了是否应该教授生活技能课。故选B。
C
Polar Bears Could Die Out by the End of the Century
The heating of Earth is pushing the number of polar bears to get smaller and smaller. According to a new study, they could die out in fewer than 100 years.
Polar bears are animals which live by eating sea seals in the Arctic Ocean. As more and more sea ice melts (融化), their living places become to shrink. The loss (丧失) of sea ice began to be paid more attention at the end of the 1970s. Since then, sea ice that lasts for more than a year in the Arctic has decreased at a rate of 13% per decade.
Studies have long shown that the growing loss of sea ice will lead to a dangerous situation for polar bears, but the new research shown in Nature Climate Change has given us a clear dying out timeline. Polar bears will be unable to live because of the climate (气候) change over the next several decades (十年). The scientists believe they will completely die out by 2100.
“What we’ve found out is that, first, it will be very difficult for cubs (幼崽) to be born and live. Even if cubs are born, the mother polar bears won’t have enough body fat (脂肪) to produce milk to bring them along through the ice-free season.” said Dr. Steven Amstrup, a scientist of Polar Bears International, to the BBC. “Any of us knows that we can’t go without food for a long time. That’s a natural need for all humans and animals.”
The research also shows that, even in a situation where many countries have done a lot of work to save polar bears, several populations (族群) of polar bears will die out. But Amstrup strongly believes that the animals can still do whatever they can do to live if the climate change does not go on getting worse.
“We must show how dangerous the situation is, because we have to do something now to stop the worst of future problems.” He said. “The way we’re on now is not good enough, but if society can do something together, we will have time to save polar bears. And if we do, we will do great good to other lives on Earth, and to ourselves too.”
27 The word “shrink” in Paragraph 2 probably means “__________”.
A. get bigger B. get lighter C. get smaller D. get heavier
28. According to the passage, polar bears will probably die out because _________.
A. sea seals in the Arctic Ocean don’t have enough body fat
B. sea ice becomes less because of the climate change
C. the new research has given a dying out timeline
D. fewer animal scientists pay attention to them
29. What is Paragraph 4 mainly about
A. Why cubs are hard to be born and live in ice-free season.
B. Why humans and animals can’t live through without food.
C. Why mother polar bears can’t produce enough milk for cubs.
D. Why Dr. Steven Amstrup does the research about polar bears.
【答案】27. C 28. B 29. A
【解析】
【导语】本文是一篇说明文，介绍了北极熊受气候变化的影响，有可能在不到一百年的时间内灭绝。文章呼吁人们携手应对气候变化，保护地球生命。
【27题详解】
词句猜测题。根据第二段“As more and more sea ice melts (融化), their living places become to shrink.”可知，海冰的不断融化使得北极熊的栖息地不断缩小，故划线部分单词与get smaller意思相近。故选C。
【28题详解】
细节理解题。根据第三段“the growing loss of sea ice will lead to a dangerous situation for polar bears”及“Polar bears will be unable to live because of the climate (气候) change over the next several decades (十年).”可知，北极熊由于气候变化导致的海冰减少而可能灭绝。故选B。
【29题详解】
段落大意题。根据第四段“first, it will be very difficult for cubs (幼崽) to be born and live…bring them along through the ice-free season”可知，文章第四段主要介绍了为什么幼崽很难出生并生活在无冰的季节。故选A。

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