阅读下面短文，掌握其大意，然后从各题所给的四个选项（A、B、C和D）中，选出最佳选项．

　　With their shiny, grey bodies, dolphins（海豚）appear to be large fish．____1____, they are really warm-blooded mammals. Although they can stay under the water for up to 15 minutes ____2____, the dolphins must come up to breathe air through a hole on top of their heads.

　　Dolphins are social animals. Many of them even ____3____ around humans. In addition to being playful; they are helpful to men. For example ____4____ 400 B.C. the Great poet Arion was saved from ___5____ by a dolphin. From then until now, dolphins have been helping swimmers, ____6__ in trouble. Swimmers, however ,are not ___7____ humans they help. In some parts of the world, they help men ____8____ fish.

　　Dolphins are very clever. Its brain is even larger than a human's. Therefore, some people think a dolphin ____9__ smarter than a man, but ____10___, brain size is not the only measure of cleverness. Besides, measuring dolphin's cleverness in other ways is not possible ___11____ men cannot talk with them. But we can almost ____12____ that dolphins can talk with each other. They make different ____13____ which seem to be at least a form of language. Up to now men ____14___ able to find out how dolphins are talking. So no one really knows what they are thinking. If we could talk with them, perhaps they could teach us to be ___15____ they seem to be.

阅读下面短文，掌握其大意，然后从各题所给的四个选项（A、B、C和D）中，选出最佳选项．

　　With their shiny, grey bodies, dolphins（海豚）appear to be large fish．____1____, they are really warm-blooded mammals. Although they can stay under the water for up to 15 minutes ____2____, the dolphins must come up to breathe air through a hole on top of their heads.

　　Dolphins are social animals. Many of them even ____3____ around humans. In addition to being playful; they are helpful to men. For example ____4____ 400 B.C. the Great poet Arion was saved from ___5____ by a dolphin. From then until now, dolphins have been helping swimmers, ____6__ in trouble. Swimmers, however ,are not ___7____ humans they help. In some parts of the world, they help men ____8____ fish.

　　Dolphins are very clever. Its brain is even larger than a human's. Therefore, some people think a dolphin ____9__ smarter than a man, but ____10___, brain size is not the only measure of cleverness. Besides, measuring dolphin's cleverness in other ways is not possible ___11____ men cannot talk with them. But we can almost ____12____ that dolphins can talk with each other. They make different ____13____ which seem to be at least a form of language. Up to now men ____14___ able to find out how dolphins are talking. So no one really knows what they are thinking. If we could talk with them, perhaps they could teach us to be ___15____ they seem to be.

下面是一篇杂志文章，请将标有A—F的段落插入文章中标号为1—5的合适位置，使这篇文章意义完整，结构连贯；其中有一个段落是多余的。

Every year more and more plants and animals disappear never to be seen again.

     1    

Every day, thousands of species of animals draw closer to extinction. There are countless numbers of species which may become extinct before they are even discovered.

    2    

The problem is acid rain. Acid rain. Acid rain is a kind of air pollution.

    3    

The rain in many places isn’t natural and clean any more. It’s full of acid chemicals.     4    

But dead fish may be just the beginning of the problem. Scientists are finding other effects of acid rain.

     5    

Now scientists are also beginning to study the effects of acid rain on larger animals. For example, they believe that some deer in Poland are less healthy because of acid rain. If deer are hurt by the rain, what about people? This is the question many people are beginning to ask. No one knows the answer yet. But it is an important question for us all.

A．Seldom does it rain and there is little fresh water here for the fish. A series of development projects has destroyed the natural environment. Waste of different kinds can be seen here and there. This has caused serious problem for fish and other animals living around.

B．In some large areas trees are dying. Not just one tree here and there, but whole forests. At first scientists coundn’t understand why. There were no bugs（虫） or diseases in these trees. The weather was not dry. But now they think that the rain was the cause. Acid rain is making the earth more acidic in these areas. Some kinds of trees cannot live in the soil that is very acidic.

C．When it falls in lakes, it changes them too. The lakes become more acidic. Acid water is like vinegar or lemon juice. It hurts when it gets in your eyes. It also kills the plants and animals that usually live in lake water. That is why the fish are dying in lakes.

D．It is caused by factories that burn coal or oil or gas. These factories send smoke high into the air. The wind often carries the smoke far from the factories.  Some of the harmful substances in the smoke may come down with the rain hundreds of miles away.

E．Strangely, it is the most intelligent but most thoughtless animal that is causing most of the problems-man. Nature is very carefully balanced and if this balance is disturbed, animals can disappear surprisingly fast.

F．In many lakes the fish are dying. Fishermen are worried because every year there are fewer fish and some lakes have no fish at all. Scientists are beginning to get worried too. What is killing

　　阅读理解。阅读下列短文，从每题所给的选项中，选出最佳答案。

　　Millions of years ago, whales lived on land and walked on four legs. Today whales still have small bones, which can only be seen on the inside of them. No one knows why whales left the land to live in the water. However, scientists can imagine when the whales changed their living conditions, their bodies underwent a change----showing a more fish----like appearance. This new form offered less resistance to the water. And the whales could swim faster.　　Whales are not fish. A whale will die, just as a man will, if it stays under water too long. When a whale is under water it closes its nose and holds is breath. The air in its lungs becomes very hot and its lungs are full of water vapour. A whale rises to the surface and breathes, its hot breath produces a fountain of water that rises high in the air. A man produces the same effect when he breathes warm air on a cold morning.

1．Today there are small bones on the inside of whales, which shows that ________.

[　　]

A．whales are fish

B．whales once lived on land

C．whales lived in the water millions of years ago

D．whales can live on land today

2．What happened to whales when they changed their living conditions?

[　　]

A．They began to leave water.

B．They began to live on land.

C．Their bodies began to change and looked like fish.

D．They changed into fish.

3．Whales can swim faster, because ________.

[　　]

A．they have smaller bones

B．their bodies have less resistance to the water

C．they often practise swimming

D．they seldom live on land

4．The word in the first paragraph “underwent” means

[　　]

A．passed through

B．brought about

C．took place

D．depended on

5．When a whale rises to the surface of the water and breathe, ________.

[　　]

A．it begins to take in warm air

B．the air in its lungs becomes very hot

C．its hot breath rises high in the air

D．the air in its lungs is changed into water vapour