What does the speaker say about animals in winter?[音频]

A. They have to look for food and shelter underground.
B. They take little notice of the changes in temperature.
C. They resort to different means to survive the bitter cold.
D. They have difficulty adapting to the changed environment.

Wha do we learn about animals that sleep through winter?

A. They have their weight reduced to minimum.
B. They consume energy stored before the long sleep.
C. They can maintain their heart beat at the normal rate.
D. They can keep their body temperature warm and stable.

How do animals like mice adapt to the severe winter?

A. By staying in hiding places and eating very little.
By seeking food and shelter in people’s houses.
C. By growing thicker hair to stay warm.
D. By storing enough food beforehand.

Why do some birds fly in groups for migrating according to the speaker?

A. To stay safe.
B. To save energy.
C. To keep company.
D. To protect the young.

What is the main idea of this passage?