Question

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Many of us feel sleepy in winter, but other species often take it a step further and hibernate (冬眠). 1. The body slows down and breathing, temperature and metabolic and heart rate all decrease. Dormice (睡鼠) head underground and hedgehogs (刺猬) hunker down in their nests.

Hibernation seems to do them good. But human cannot bed down for long periods. 2. To work out why we do not, first we need to find out why animals do. The most obvious reason for hibernating is to avoid the cold. Conditions are harsh and there is little food to eat, as fewer plants are growing. 3. Then they live off body-fat reserves until it’s time to wake up.

But a 2015 study of dormice found that they continued hibernating even when cold conditions had ended. 4. The key issue seemed to be connected with their main food: beech trees. The dormice need their seeds to reproduce, or for the baby dormice to gain enough body fat. In a harvest year, they produce plenty of seeds. Somehow the dormice could predict it. Otherwise, they stop reproduction these years and increase their survival by staying underground.

5. By staying out of sight, the dormice avoided being hunted by their predators (天敌) like owls. Until recently people thought hibernation was just about energy saving, a defense against cold weather and food shortage, and now we think it’s more predator avoidance. The survival rates in hibernation are close to 100%.

A. So obviously there are other reasons.

B. They were hibernating underground to save energy.

C. Hibernation is an extended period of energy-saving state.

D. All kinds of animals hibernate, from insects to birds and primates.

E. Why, if it is so beneficial, do we not hibernate?

F. The dormice had another reason to stay underground.

G. So many animals fatten themselves up during summer.

Answer 1