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The world is not only hungry, but it is also thirsty for water．This may seem strange to you，since nearly 70 percent of the earth's surface is covered with water．But about 97 percent of this huge amount is sea water, or salt water．Man can only drink and use the other 3 percent-the fresh water from rivers，lakes，underground，and other sources．And we cannot even use all of that，because some of it is in the form of icebergs and glacier．Even worse，some of it has been polluted．

However，as things stand today, this small amount of fresh water is still enough for us．But our need for water is increasing rapidly-almost day by day．Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on．

We all have to learn how to stop wasting our valuable water．One of the first steps is to develop ways of reusing it．

Today in most large cities，water is used only once and then sent out into a sewer system．From there it returns to the sea or runs into underground storage tanks．But it is possible to pipe used water to a purifying plant．There it can be treated with chemicals so that it can be used again，just as if it were fresh from a spring．

But even if every large city purified and reused its water，we still would not have enough．All we'd have to do make use of the vast reserves of sea water in the world is to remove the salt．

If we take these steps we'll be in no danger of drying up．

56．The world is thirsty for water because we can only use      percent of the water covering the surface of the earth．

A．3    B．more than 3    C．less than 3    D．97

57．Which of the following statements is NOT TRUE?

A．As things remain unchanging，this small amount of fresh water is still enough for us．

B．Our need for water is becoming larger and larger．

C．There will be no water shortage in the future．

D．We should take steps to deal with the water shortage problem．

58．To reuse water, we should              ．

A．treat it with chemicals              B．use it only once

C．send it out into a sewer system       D．make it flow into underground tanks

59．In order to have enough water．we should also make use of          ．

A．icebergs and glaciers    B．sea water

C．rivers and lakes        D．underground water

The world is not hungry, but it is thirsty. It seems strange that nearly 3/4 of the earth is covered with water while we say we are short of water. Why? Because about 97% of water on the earth is sea water which we can’t drink or use for watering plants directly. Man can only drink and use the 3% the water that comes from rivers and lakes. And we can’t even use all of that, because some of it has been polluted.

Now more water is needed. The problem is: can we avoid a serious water shortage later on? First, we should all learn how to save water. Secondly, we should find out the ways to reuse it. Scientists have always been making study in this field. Today, in most large cities water is used only once and then runs to the sea or rivers. But it can be used again. Even if every large city reused its water, still there would not be enough. What could people turn to next?

The sea seems to have the best answer. There is a lot of water in the sea. All that needs to be done is to get the salt out of the sea water. This is expensive, but it’s already in use in many parts of the world. Scientists are trying to find a cheaper way of doing it. So you see, if we can find a way out, we’ll be in no danger of drying up.

1.The world is thirsty because ___________.

2.Which of the following is TRUE?

3.From the passage we learn that __________.

The world is not hungry, but it is thirsty. It seems strange that nearly 3/4 of the earth is covered with water while we say we are short of water. Why? Because about 97% of water on the earth is sea water which we can’t drink or use for watering plants directly. Man can only drink and use the 3% the water that comes from rivers and lakes. And we can’t even use all of that, because some of it has been polluted.
Now more water is needed. The problem is: can we avoid a serious water shortage later on? First, we should all learn how to save water. Secondly, we should find out the ways to reuse it. Scientists have always been making study in this field. Today, in most large cities water is used only once and then runs to the sea or rivers. But it can be used again. Even if every large city reused its water, still there would not be enough. What could people turn to next?
The sea seems to have the best answer. There is a lot of water in the sea. All that needs to be done is to get the salt out of the sea water. This is expensive, but it’s already in use in many parts of the world. Scientists are trying to find a cheaper way of doing it. So you see, if we can find a way out, we’ll be in no danger of drying up.
【小題1】The world is thirsty because ___________.

The world is not only hungry, but it is also thirsty for water．This may seem strange to you，since nearly 70 percent of the earth's surface is covered with water．But about 97 percent of this huge amount is sea water, or salt water．Man can only drink and use the other 3 percent-the fresh water from rivers，lakes，underground，and other sources．And we cannot even use all of that，because some of it is in the form of icebergs and glacier．Even worse，some of it has been polluted．
However，as things stand today, this small amount of fresh water is still enough for us．But our need for water is increasing rapidly-almost day by day．Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on．
We all have to learn how to stop wasting our valuable water．One of the first steps is to develop ways of reusing it．
Today in most large cities，water is used only once and then sent out into a sewer system．From there it returns to the sea or runs into underground storage tanks．But it is possible to pipe used water to a purifying plant．There it can be treated with chemicals so that it can be used again，just as if it were fresh from a spring．
But even if every large city purified and reused its water，we still would not have enough．All we'd have to do make use of the vast reserves of sea water in the world is to remove the salt．
If we take these steps we'll be in no danger of drying up．
56．The world is thirsty for water because we can only use      percent of the water covering the surface of the earth．
A．3    B．more than 3    C．less than 3    D．97
57．Which of the following statements is NOT TRUE?
A．As things remain unchanging，this small amount of fresh water is still enough for us．
B．Our need for water is becoming larger and larger．
C．There will be no water shortage in the future．
D．We should take steps to deal with the water shortage problem．
58．To reuse water, we should              ．
A．treat it with chemicals              B．use it only once
C．send it out into a sewer system       D．make it flow into underground tanks
59．In order to have enough water．we should also make use of          ．
A．icebergs and glaciers    B．sea water
C．rivers and lakes        D．underground water

The world is not only hungry, but it is also thirsty for water．This may seem strange to you，since nearly 70 percent of the earth's surface is covered with water．But about 97 percent of this huge amount is sea water, or salt water．Man can only drink and use the other 3 percent-the fresh water from rivers，lakes，underground，and other sources．And we cannot even use all of that，because some of it is in the form of icebergs and glacier．Even worse，some of it has been polluted．

However，as things stand today, this small amount of fresh water is still enough for us．But our need for water is increasing rapidly-almost day by day．Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on．

We all have to learn how to stop wasting our valuable water．One of the first steps is to develop ways of reusing it．

Today in most large cities，water is used only once and then sent out into a sewer system．From there it returns to the sea or runs into underground storage tanks．But it is possible to pipe used water to a purifying plant．There it can be treated with chemicals so that it can be used again，just as if it were fresh from a spring．

But even if every large city purified and reused its water，we still would not have enough．All we'd have to do make use of the vast reserves of sea water in the world is to remove the salt．

If we take these steps we'll be in no danger of drying up．

1.The world is thirsty for water because we can only use       percent of the water covering the surface of the earth．

A．3    B．more than 3    C．less than 3    D．97

2.Which of the following statements is NOT TRUE?

A．As things remain unchanging，this small amount of fresh water is still enough for us．

B．Our need for water is becoming larger and larger．

C．There will be no water shortage in the future．

D．We should take steps to deal with the water shortage problem．

3.To reuse water, we should              ．

A．treat it with chemicals              B．use it only once

C．send it out into a sewer system       D．make it flow into underground tanks

4.In order to have enough water．we should also make use of           ．

A．icebergs and glaciers    B．sea water

C．rivers and lakes        D．underground water