③If you want to be a performer，you will have to keep up your piano．如果你真想成为演奏家，就得坚持练习钢琴．3.Then it as no choice but to lie down and sleep．于是，别无选择，它们只好躺下睡觉。
have no choice but to do表“别无选择”之意。eg．Have I any choice but to do as you tell me？ 除了按你吩咐的去做外，我还有别的选择吗？
表示“别无选择只好做……”之意，除了可用 have no choice but to do…来表达外，还可用下列固定搭配：（l）can do nothing but do／can not do anything but do，eg．I can do nothing but accept his demand．我只好接受他的要求。
（2）there is nothing left to do but do…，eg．There was nothing left for her to do but cry．她别无它法，只有哭。
（3）can’t but do…，eg．I could not but admit that he was right and. I was wrong．我不得不承认他对了，我错了。
疑难点拨：
1.Hibernation is more than sleep．冬眠不仅仅是睡眠。
句中的more than相当于 not only。意为“不仅仅”，e．g．He is more a teacher．He is a good friend of mine。他不只是老师，还是我的益友。
2．People who find hibernating animals asleep often think that they are dead.人们看到处于冬眠状态的动物，常常以为它们死了。
这是一个复合句。
（l）who－clause是定语从句修饰people，that－clause是宾语从句作think的宾语。
（2）asleep是表语形容词，在句中一般只作表语，宾补，或后置定语，这样的形容词还有alive，alike，alone，awake等。
3．You can touch it， or even pull its tail without causing it to move or wake up. 你可以摸它，甚至可以拉它的尾巴，这也不会使它动一动或醒过来。
这个句子可改写成：Even if you touch it or pull its tail，you can’t cause it move or wake up.
4. Hibernating in that way， the animal can sleep all through the winter.
用那种方式冬眠，动物可以睡过整过冬天。
句中的 hibernating in that way是现在分词短语在句中作状语，相当于as they hibernate in that way。
5．We have seen that hibernating animal reduces movements to far below the ordinary level.
冬眠动物的活动量减少到远远低于一般水平。
（1）句中的 far below意为“远远低于，比……低得多”。e．g．In winter the temperature of Harbin is far below that of Wuhan．冬天哈尔滨的气温比武汉的低得多。
（2）句中的reduce…to作“减少，使处于……状态”解。e．g．① The house was reduced to ashes by the big fire.那场大火把屋子化为灰烬。
②The man was reduced to begging for food．那男人沦落到讨饭的地步。
Step4：Fill in blanks.
1. They go to sleep in all kinds of places. Red squirrels disappear inside trees， bears use caves， frogs go deep under the mud， and many other animals dig holes in the earth .A good many animals sleep under the snow. There is a lot of air in loose snow， and this helps to keep the cold out.
2. Hibernation is more than sleep. It is a very deep sleep.the animal’s temperature drops to just over zero centigrade， and its heart beats very slowly.People who find hibernating animals asleep often think that they are dead； the body feels very cold， and the animal may breathe only once every five minutes. A hibernating animal cannot feel any pain. You can touch it ， or even pull its tail， without causing it to move or wake up.
3.Hibernating in that way， the animal can sleep all through the winter. You might wonder how it manages to live withut eating for so many months 。 The answer lies in two facts. The first is that it has stored supplies of fat in its body during the summer and autumn. The second is conneted with the main use the body makes of food—— to supply the energy for movement. We have seen that the hibernating animal reduces movement to far below the ordinary level. Even the movements of the heart and lungs are greatly reduced.The animal hardly makes any movement，hardly uses any energy， and hardly needs any food.
Step5：Homework：Write a summary of the test.
