You will listen to part of a lecture and answer a question about it. After you hear the question, you will have 20 seconds to pr

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问题 You will listen to part of a lecture and answer a question about it. After you hear the question, you will have 20 seconds to prepare a response and 60 seconds to record the response.
Now listen to part of a lecture in a biology class.
Using points and examples from the lecture, explain two adaptations that help polar bears survive in their Arctic environment.
Now listen to part of a lecture in a biology class.
    You’ve seen all pictures of polar bears, right? Those are the giant white bears that live in the Arctic, up near the North Pole where it’s extremely cold and snowy for much of the year. Well, as you can imagine, polar bears have to spend a lot of time swimming around in the icy, cold water of the Arctic Ocean, so polar bears have developed certain bodily features, or adaptations that help them stay warm in the freezing Arctic environment. Let’s talk about a couple of these adaptations.
    First, polar bears have an adaptation to help them hold in the heat of the sun. As you know, dark colors absorb more sunlight than lighter colors do, so an animal living in the cold can stay warmer if the animal has dark coloring. For example, even though polar bears have white fur, the skin underneath their fur is black, so when sunlight comes through the fur and hits their skin, the black skin absorbs a lot of light and heat from the sun and warms up their bodies.
    Polar bears also have another adaptation against the cold. This one prevents the cold water from reaching their skin. As I’ve said, they spend a lot of time swimming in icy water. If that water got soaked into their fur, the fur wouldn’t be able to insulate the bears and keep them warm, so they have an adaptation that prevents that from happening. For example, polar bears naturally have oily fur. Yes, their fur actually has oil on it and this oil helps repel water and makes their fur waterproof. In that way, the fur can continue to keep the bears warm even while they’re swimming.

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答案 To survive freezing weather in the Arctic, polar bears have developed many bodily features, or adaptations that keep themselves warm in the coldest days. Specifically, there’re two adaptations that help them guard against the coldness. One adaptation is their skin. Although polar bears have white fur, the skin underneath is black. The black skin is able to take in more sunlight and heat than light-colored skin, and thus helping their body warm up. The other adaptation is their naturally oily fur. The oil of their fur can drive off water and protect them from being soaked. With this waterproof fur, they can stay warm, even when swimming in the icy water of the Arctic Ocean for an extended period of time.

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