|http://www.sina.com.cn 2003/10/17 12:26 新浪教育|
Some birds will fly away to the south when the weather turns cold. Other
birds and all animals stay with you, but you will not see all the animals
throughout the winter. In the cold weather some of them hibernate.
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.
Some warmblooded animals, like the cat, the dog or the wolf, do not
need to hibernate; they lead an active life which keeps up their normal body
temperature even in very cold winter weather. But for a coldblooded animal
such as a frog or a snake it is a different matter. When the air temperature is
below freezing, its body temperature drops too. It cannot move about in its
usual way. Then it has no choice but to lie down and sleep. To do that, it
must find a placeswheresit can keep fairly warm; and it must be a place where
its enemies cannot find it.
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.
Hibernating in that way, the animal can sleep all through the winter. You
might wonder how it manages to live without 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 connected 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.
Some animals, including some bears, only halfhibernate. That is to say,
they sleep during the winter but their sleep is not such a deep one, and their
body temperature does not drop. In autumn the bear eats and eats and becomes
very fat indeed. Its hair grows longer. Soon it has a thick covering of fat and
fur. In November it finds a place in a cave or under a tree and just lies down
and goes to sleep. On warm winter days it may think that spring has arrived; it
gets up and walks around. When it sees that the snow is still thick on the
ground, it quickly goes to sleep again.
The squirrel is an animal which makes secret food stores for the winter. It
hides large quantities of nuts inside trees. In old stories, the squirrel was usu-
ally described as a good animal: it saved something for the future.
The plane made some circles and then flew away.
People will not see all the animals throughout the winter.
辨析：all over一般只指空间; all through一般只指时间; throughout时间，空间均可。
3go to sleep入睡
Finally the children went to sleep.最后孩子们睡着了。
辨析：go to bed意思是“上床去睡觉”“就寝”，瞬间性动作词组；go to sleep意思是“睡着”，“去睡觉了”，瞬间性词组；fall asleep
4a good many很多
There are a good many books in the reading room.
辨析：many a或more than one也表“很多；许多”；但many a修饰主语时，谓语要用单数形式。
Qin Shihuang had the Great Wall built to keep the enemy out of his empire.
Sports can keep up your body temperature in winter.
7主语+has no choice but+to do sth.……除了……别无选择
The enemy could do nothing but lay down their arms.敌人只能放下武器。
句型链接：can do nothing but+动词原形只能做……
Hard work leads to success and failure often lies in laziness.
He reduced his speed to 40 kilometers an hour when he entered the city.
10far below :远远低于，比……低得多
The production of their factory was far below the normal level last year.
11that is to say也就是说
They are not common friends, that is to say, they have special relation.
12a thick covering of厚厚的一层
There is a thick covering of leaves in the forest, which are very easy to catch fire.
|【英语学习论坛】【评论】【大 中 小】【打印】【关闭】|