Official 31 Task 4
精听文本
Listening
00:00
00:00
查看文本
Narrator: Listen to part of a lecture in a Biology class.
Professor: Even though it's cold and snow-covered,
the Arctic houses many species of animals that manage to survive the harsh conditions there.
These Arctic animals have adapted to the extremely cold temperatures,
primarily because of certain body features that help them to survive in the cold Arctic climate.
Let's look at a few of them.
For one thing, many Arctic animals have developed a protective covering on their feet.
The covering usually consists of fur or feathers,
which act as a protective layer between the cold and the animal skin.
Since they spend so much of their time on snowy icy surfaces,
whether they are standing on the ground or swimming in the water,
they can easily lose heat through their feet.
This is especially true of Arctic birds.
A bird like the Arctic snowy owl, for example, has feathers on its body the way other birds do.
But unlike most birds,
it also has feathers all over its feet.
This shields and protects the feet from the icy ground,
so that very little of the owls foot actually touches snowy or icy surfaces,
which helps its feet to stay warm.
Another physical characteristic that some Arctic animals share,
is having smaller bodies and smaller, shorter body parts.
In other words,
their bodies are often more compact than other animals,
and the parts of their bodies that stick out or protrude,
like the legs, ears or tails are smaller and shorter.
And the result is that there is less body surface exposed to the cold air.
A great example is the Arctic wolf.
Unlike the larger grey wolves that live in warmer climates,
Arctic wolves have relatively small, compact bodies that efficiently retain heat.
They also have smaller ears and shorter legs,
so they lose less body heat than animals with larger bodies or longer body parts.
And in a climate where the temperature is below zero most of the year, that's very important.
Question

Using the example of the owl and the wolf, explain how two special body features have helped arctic animals adapt to the cold.