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Most polar bears could disappear by the end of the century because of global warming, scientists say.
According to a study in Nature Climate Change, the number of polar bears will fall quickly by 2080. One of the reasons is that the sea ice is melting. Polar bears catch seals(海豹) to eat on the ice. Without ice, they have to stay on land. But there is not enough food on land to support so many polar bears. The animals could die from hunger. The other reason is that mother polar bears may not be fat enough to provide milk for their babies, so some bears stop having babies.
Polar bears are the largest land animals on the planet that eat meat. They help control other kinds of animals. Losing them would break the balance of their living place.
The Arctic Ocean(北冰洋) is the home of about 25,000 polar bears. Arctic sea ice usually melts in spring and summer, and then grows in winter. But now, the ice is taking longer to grow back. Scientists say the Arctic is warming twice as fast as the rest of the planet.
The study also shows that it is possible to slow Arctic ice melting. Greenhouse gases(温室气体) could lead to climate change. In order to stop creating greenhouse gases, the world should try to give up burning coal(煤炭) and riding in cars.
Saving the bears is meaningful to us. Holland, one of the writers of the study, says, "I believe there is hope, but humans need to act quickly to make that hope come true." Let's take action to save polar bears.
() 4. How many reasons are mentioned to show why polar bears are in danger?
A. One.
B. Two.
C. Three.
D. Four.
() 5. According to the passage, the climate change makes Arctic sea ice .
A. stop growing back in winter
B. keep melting in spring and winter
C. melt twice faster than the rest of the planet
D. take more time to grow back in winter
() 6. What is the main purpose of this passage?
A. To show the importance of ice.
B. To make people like polar bears.
C. To ask people to protect polar bears.
D. To explain natural climate change.
Most polar bears could disappear by the end of the century because of global warming, scientists say.
According to a study in Nature Climate Change, the number of polar bears will fall quickly by 2080. One of the reasons is that the sea ice is melting. Polar bears catch seals(海豹) to eat on the ice. Without ice, they have to stay on land. But there is not enough food on land to support so many polar bears. The animals could die from hunger. The other reason is that mother polar bears may not be fat enough to provide milk for their babies, so some bears stop having babies.
Polar bears are the largest land animals on the planet that eat meat. They help control other kinds of animals. Losing them would break the balance of their living place.
The Arctic Ocean(北冰洋) is the home of about 25,000 polar bears. Arctic sea ice usually melts in spring and summer, and then grows in winter. But now, the ice is taking longer to grow back. Scientists say the Arctic is warming twice as fast as the rest of the planet.
The study also shows that it is possible to slow Arctic ice melting. Greenhouse gases(温室气体) could lead to climate change. In order to stop creating greenhouse gases, the world should try to give up burning coal(煤炭) and riding in cars.
Saving the bears is meaningful to us. Holland, one of the writers of the study, says, "I believe there is hope, but humans need to act quickly to make that hope come true." Let's take action to save polar bears.
() 4. How many reasons are mentioned to show why polar bears are in danger?
A. One.
B. Two.
C. Three.
D. Four.
() 5. According to the passage, the climate change makes Arctic sea ice .
A. stop growing back in winter
B. keep melting in spring and winter
C. melt twice faster than the rest of the planet
D. take more time to grow back in winter
() 6. What is the main purpose of this passage?
A. To show the importance of ice.
B. To make people like polar bears.
C. To ask people to protect polar bears.
D. To explain natural climate change.
答案
4. B 5. D 6. C
解析
4. 细节理解题。根据文章第二段内容，文中用"One of the reasons..."和"The other reason..."明确引出了两个北极熊陷入生存危机的原因：一是海冰融化后北极熊在陆地上没有充足食物，可能饿死；二是北极熊妈妈没有足够的脂肪给幼崽哺乳，部分北极熊停止繁育后代，一共提到2个原因。
5. 细节理解题。根据文章第四段"Arctic sea ice usually melts in spring and summer, and then grows in winter. But now, the ice is taking longer to grow back."可知，气候变化让北极海冰在冬季需要花费更长时间才能重新结冰。A选项“冬季完全停止恢复结冰”、B选项“春季和冬季持续融化”均不符合原文内容；C选项描述的是北极整体变暖的速度是地球其他区域的两倍，并非海冰的变化，因此选D。
6. 主旨大意题。本文先介绍全球变暖背景下北极熊面临的生存危机，解释危机出现的原因，最后发出倡议号召大家行动起来拯救北极熊，全文核心写作目的是呼吁人们保护北极熊。
5. 细节理解题。根据文章第四段"Arctic sea ice usually melts in spring and summer, and then grows in winter. But now, the ice is taking longer to grow back."可知，气候变化让北极海冰在冬季需要花费更长时间才能重新结冰。A选项“冬季完全停止恢复结冰”、B选项“春季和冬季持续融化”均不符合原文内容；C选项描述的是北极整体变暖的速度是地球其他区域的两倍，并非海冰的变化，因此选D。
6. 主旨大意题。本文先介绍全球变暖背景下北极熊面临的生存危机，解释危机出现的原因，最后发出倡议号召大家行动起来拯救北极熊，全文核心写作目的是呼吁人们保护北极熊。
