Question

高三牛津英语unit4 More reading课文原文

Answer 1

What do bears,bats and frogs have in common?They all hibernate.Hibernation si a state often compared to sleep.It often occrus in winter,when a creature does not move for weeks or months continuously.Creatures hibernate to survive the cold weather and the absence of food.
A topical example of a hibernating creature is the bat.When winter comes,bats find a safe place in a cave.Looking like they a dead,they hang upside down.Their pulse and brething rates greatly slow down.Their body temperatures drop as well.these things help them save energy during long winters when it is difficult to find food.
Frogs,like many amphibians,also hibernate when it gets cold.After digging deep into the mud at the bottom of a pond,they do not stir again until it is warm.During hibernation,they breathe through their skins,not their mouths.
Another hibernating creature is the bear.Incontrast to other creatures,hibernating bears do not appear as though they are dead,but seem as though they are very sleepy.If they are disturbed during hibernation,they can get up very quickly.While hibernating,bears stay in their dens,which are filled with leaves to make their stay more comfortable and warmer.In spring,having awakened,they leave their dens,thin and hungry.