Hibemation(冬眠)is a way for some animals to deal with the harshness of winter.They seek out a place where. The will be protected from the weather and stay ___16___ the winter is over.During hibernation aninfals curl up and ___17___ breathe,seeming almost dead.Their hrart rate and blood pressure are greatly ___18___, and their body temperature hovers near the freezing ___19___.When the weather turns warmer,the animals come out of this state and return to ___20___ activities.
Hibermators try to find dark,quiet,safe winter homes where they will not be ___21___.They may make a den more ___22___ by filling it with grass,hair and other materials.In ___23___, many animals that normally hibernate may have to stay active during the winter because of noise and ___24___.
Before winter comes,hibernators spend much of their time eating to ___25___more baby fat.This extra fat keeps them ___26___ during the months when they do not eat.A hibernator's body is sensitive ___27___ weather conditions.At different points during hibernation, these animals will increase their body temperature,move around,eat and then ___28___ to hibermating.An animal that does not do this may freeze to death.Similarly,animals respond to warmer temperatuies ___29___ to come out of hibermation.It may take an hour or more for a hibemation to reach an alert state.
The knowledge on hibemation has been used on patients ___30___certain types of surgery.It may be possible that hibernation could also someday help space travelers by decreasing their need for oxygen and food.
回答第（25）问
A、carry on
B、build on
C、put on
D、catch on
【正确答案】：C
