How does a whale keep itself warm?

A、 By its thick layer of fat under its skin.
B、 By moving frequently in the water.
C、 By adjusting its blood temperature.
D、 By taking in hot air.

【正确答案】 A

【答案解析】

单选题 What do we learn about the blood temperature of a whale?

A、 Grows colder as the blubber accumulates.
B、 Remains the same.
C、 Varies according to the water temperature.
D、 Grows warmer as the whale grows older.

【正确答案】 B

【答案解析】

单选题 In what way do whales distinguish themselves from other land mammals?

A、 They have very few hairs on their bodies.
B、 They bear their young rather than laying eggs.
C、 Their lungs are full of hot air and water.
D、 They can walk on their hind legs on land.

【正确答案】 A

【答案解析】