Polar bears live________ on sea ice, which th...

Polar bears live      on sea ice, which they use as a platform for hunting seals.

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Polar bears live________ on sea ice, which they use as a platform for hunting seals.

A．most B．almost   C．nearly   D．mostly

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Polar bears live in environments too cold for most1.(animal).For much of the year,they live and hunt on the 2.(freeze) Arctic sea ice.Nature has prepared them for the cold conditions.But nothing has prepared the bears for the danger3.threatens the only home they know.

The polar bears' world is melting.Studies show that the polar ice4.(reduce) by 9.8% every 10 years since l978.Now about 20,000 to 25,000 polar bears live in the Arctic.Polar bears depend on the sea ice for their5. (survive)."The sea ice is more6.just this platform that the bears walk over,"says Andrew Derocher,a scientist who studies North American polar bear populations."Without7.,they can't exist."

Some melting and refreezing of the polar ice is8.(nature).But in a warmer world,these cycles speed up,and bears have9.(little) time to hunt.Normally,they have three months in the spring when they gain more weight.The extra fat is used10.(late),when the bears are not actively hunting.

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概要写作

阅读下面短文，根据其内容写一篇60词左右的内容概要。

With global warming and melting ice, it isn’t easy being a polar bear anymore. Some studies have predicted that polar bears could die out by the end of the century. The good news is not all researchers think the bears are absolutely disappearing. Scientists at the American Museum of Natural History(AMNH) have published a new paper indicating that things might not be as bad for polar bears as some scientists expect.

To understand the reason for the researchers’ cautious optimism, we must first understand the factors that are threatening the polar bear’s existence. Polar bears consume a diet of mainly young seals. In order to hunt these seals, polar bears need to rest at the top of sea ice---the same ice that is increasingly melting for most of the year thanks to climate change. In another 50 years, experts expect that the Arctic will be too warm for sea ice to form for half of the year, leaving polar bears without a reliable food source and in serious danger of starvation.

As it turns out, alternative food sources for the polar bears aren’t completely out of the question. For as long as biologists have tailed after the animals, they’ve seen polar bears eating animals found on land like caribou(驯鹿) and snow geese---as well as the snow geese’s eggs.

Can polar bears actually survive off these alternative food sources for long periods of time? To figure this out, researchers calculated the nutrients that a caribou and snow geese diet would provide. They found that even adult male polar bears would be able to obtain more calories than they would burn in hunting these meals. Moreover, the food would provide the food necessary to avoid starvation during the summer months.

Unfortunately, not all polar bears have tended to seek food on land. That said, the researchers expect that necessity would push more polar bears to hunt on land to avoid starvation. They also expect that the bears could learn from their fellow bears how to hunt on land until the practice becomes second nature.

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阅读下面短文, 根据其内容写一篇60词左右的内容概要。

With global warming and melting ice, it isn’t easy being a polar bear anymore. Some studies have predicted that polar bears could die out by the end of the century. The good news is not all researchers think the bears are absolutely disappearing. Scientists at the American Museum of Natural History(AMNH) have published a new paper indicating that things might not be as bad for polar bears as some scientists expect.

To understand the reason for the researchers’ cautious optimism, we must first understand the factors that are threatening the polar bear’s existence. Polar bears consume a diet of mainly young seals. In order to hunt these seals, polar bears need to rest at the top of sea ice---the same ice that is increasingly melting for most of the year thanks to climate change. In another 50 years, experts expect that the Arctic will be too warm for sea ice to form for half of the year, leaving polar bears without a reliable food source and in serious danger of starvation.

As it turns out, alternative food sources for the polar bears aren’t completely out of the question. For as long as biologists have tailed after the animals, they’ve seen polar bears eating animals found on land like caribou(驯鹿) and snow geese---as well as the snow geese’s eggs.

Can polar bears actually survive off these alternative food sources for long periods of time? To figure this out, researchers calculated the nutrients that a caribou and snow geese diet would provide. They found that even adult male polar bears would be able to obtain more calories than would burn in hunting these meals. Moreover, the food would provide the food lecessary to avoid starvation during the summer months.

Unfortunately, not all polar bears have tended to seek food on land. That said, the researchers expect that necessity would push more polar bears to hunt on land to avoid starvation. They also expect that the bears could learn from their fellow bears how to hunt on land until the practice becomes second nature.

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高二英语书面表达中等难度题查看答案及解析

Polar bears are suffering in a1. (warm) world than ever before.

Polar bears live in environments too cold for most animals. For much of the year, 2.live and hunt on the frozen Arctic sea ice. Nature has prepared them for the cold conditions. But nothing has prepared the bears for the danger threatening the only home3.they know.

The polar bears’ world is melting. Studies show that the polar ice4.(reduce) by 9.8% every 10 years since 1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their5. (survive). “The sea ice is more than just this platform that the bears walk over.” says Andrew Derocher, 6.scientist who studies North American polar bear populations. “7.it, they can’t exist.”

Some melting and refreezing of the polar ice is natural. 8.in a warmer world, these cycles speed up, and bears have less time9.(hunt). Normally, they have three months in the spring when they gain more weight. The extra fat is used later, 10. the bears are not actively hunting.

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Polar bears are suffering in a 1. (warm) world than ever before.

Polar bears live in environments too cold for most animals. 2. much of the year, they live and hunt on the frozen Arctic sea ice. Nature has prepared  3.  for the cold conditions. But nothing has prepared the bears for the danger that 4.(threat) the only home they know.

The polar bears’ world is melting. Studies show that the polar ice has reduced by 9.8% every 10 years 5.1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their 6. (survive). “The sea ice is more than just this platform that the bears walk over,” says Andrew Derocher ,  7. scientist who studies North American polar bear populations. “  8. it, they can’t exist.”

Some melting and refreezing of the polar ice is natural. 9.  in a warmer world, these cycles speed up, and bears have less time to hunt. Normally, they have three months in the spring when they gain more weight. The extra fat is used later,  10. the bears are not actively hunting.

高二英语短文填空中等难度题查看答案及解析

Polar bears are suffering in a　 1.(warm) world.

Polar bears live in environments too cold for most animals.2.much of the year, they live and hunt on the frozen Arctic sea ice. Nature has prepared 3.for the cold conditions. But nothing has prepared the bears for the danger that 4. (threat)the only home they know.

The polar bears’ world is melting. Studies show that the polar ice has reduced by 9.8% every 10 years 5. 1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their 6. (survive). “The sea ice is more than just this platform that the bears walk over,” says Andrew Derocher, 7. scientist who studies North American polar bear populations. “8. it, they can’t exist.”

Some melting and refreezing of the polar ice is natural. 9. in a warmer world, these cycles speed up, and bears have less time to hunt. Normally, they have three months in the spring when they gain more weight. The extra fat is used later,  10. the bears are not actively hunting.

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Polar bears are suffering in a much 1. (warm) world.

Polar bears live in environments too cold for most animals. During much of the year, they live and hunt on the frozen Arctic sea ice. Nature has 2. （prepare）them for the cold conditions. But nothing has prepared the bears for the danger 3. threatens the only home they know.

The polar bears’ world is melting. Studies show that the amount of the polar ice 4.（have）decreased by 9.8% every 10 years since 1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears rely 5.the sea ice for their survival. “The sea ice is more 6. just this platform that the bears walk over,” says Andrew Derocher, 7. scientist who studies North American polar bear populations. “8. it, they can’t exist.”

Some melting and refreezing of the polar ice is natural. But in a warmer world, these cycles speed up, and bears have less time 9. (hunt). Normally, they have three months in the spring when they gain more weight. The extra fat is used later, when the bears are not 10.

(active) hunting.

高二英语短文填空中等难度题查看答案及解析

Many people may not believe it, but this is what is happening: polar bears are dying out! They are dying because they are losing a great deal of habitat due to human incursion（侵入）and global warming.　 They are dying because of starvation as well.　 With the sea ice they depend on for survival shrinking, it is becoming increasingly difficult for them to find food.

An ecosystem is highly dependent on all of its parts, and removing even a single species can result in serious consequences.　 Polar bears are at the top of the predators（捕食性动物）where they live.　 They play an important part in the ecosystem.　 They feed on seals, fish and deer.　 Several other animals depend on the kill of polar bears.　 The failure to save polar bears might result in loss of these predators.

In addition, all large predators perform a very important function in their habitat: helping to control the populations of other species.　 When an animal group loses its natural predators, its population will rise rapidly, having a direct result in population decrease of other groups.　 A huge boom in population of Arctic seals would have a direct effect on the prey(捕食) of seals, and could reduce numbers of certain types of fish.

This could also have a direct effect on humans, who might have to compete with Arctic seals for food supplies from fish. Lack of polar bears could eventually affect human food supply. Human beings shall save polar bears to ensure the food supply.

There is no doubt that we should save polar bears.　 However, there is still another question: can they be saved? This is a matter that scientists debate because of rapid degradation（恶化）of the polar bear’ environment in recent years due to warming temperatures.　 It is estimated that if the bears cannot adapt to changing climates, they might die out before the end of the 21st century, with about 50% of the animals disappearing by 2050. So time is running out!

There are some things that may help slow down global warming and help delay extinction of polar bears.　 These include finding new energy sources that don’t give off greenhouse gases and not making any more incursions into polar bear’s territory.

1.Which is NOT the threat to the survival of polar bears according to the passage?

A. Human’s killing.　　　 B. Global warming.

C. Habitat loss.　　　　 　　 D. Lack of food.

2.Why do we need to save polar bears?

A. For the predators in the ecosystem.

B. For the seals in Arctic Circle.

C. For our own source of food.

D. For our environment.

3.If bears can’t adapt to changing climates, we will probably have lost 　　 _____　 by the middle of the 21st century.

A. half of polar bears

B. most of polar bears

C. 90% of polar bears

D. all of polar bears

4.We can infer that 　 _____　　 .

A. nothing can prevent the extinction of polar bears

B. drilling for oil in the Arctic should be encouraged

C. polar bears can surely adapt to changing climates

D. using solar energy is good for saving polar bears

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