A Thirsty World
The world is not only hungry, it is also thirsty for water. This may seem strange to you, since nearly 75% of the earth's surface is covered with water. But about 97% of this huge amount is sea-water, or salt water. Man can only drink and use the other 3% - the fresh water that comes 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 （冰山） and glaciers （冰川）. Even worse, some of it has been polluted.
At the moment, this small amount of fresh water is still enough for us. However, our need for water is increasing rapidly. Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on. A limited water supply would have a bad effect on agriculture and industry.
In addition to stopping wasting our precious water, one useful step we should take is to develop ways of reusing it. Experiments have already been done in this field, but only on a small scale.
Today, in most large cities, water is used only once and it eventually returns to the sea or runs into underground storage tanks. But it is possible to pipe water that has been used to a purifying （净化） plant. There it can be filtered （过滤） and 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. Where could we turn next? To the oceans! All we'd have to do to make use of the vast amount of sea-water is - remove the salt. This salt-removing process is already in use in many parts of the world.
So if we take all these steps, we'll be in no danger of drying up!
31 The phrase "the world" in the first line of the passage refers to
32 What percentage of the earth's water can man actually use at present?
A Nearly 75 per cent.
B About 97 per cent.
C Exactly 3 per cent.
D Less than 3 per cent.
33 According to the passage, we can avoid a worldwide water shortage in the future by
A increasing rainfall.
B reusing water and utilizing sea-water.
C cutting down our consumption of water.
D reducing the number of factories producing steel.
34 Which of the following statements, according to the passage, is NOT true?
A A limited water supply will affect industrial production.
B Every large city purifies and reuses its water.
C Purified water is not exactly as fresh as spring water.
D Oceans are the largest water source.
35 According to the passage, sea-water can be turned into fresh water by
A heating it up.
B treating it with chemicals.
C taking salt out of it.
D drying it up.
Life in the Universe
Many scientists today are convinced that life exists elsewhere in the universe —— life probably much like that on our own planet. They reason in the following way.
As far as astronomers （天文学家） can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.
Life also requires a steady supply of heat and light. This eliminates double stars, or stars that flare up （闪耀） suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life? First, eliminate those stars that are not like our sun. Next, eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
36 Astronomers believe that matter in different parts of the universe
A obeys different laws.
B obeys one common law.
C obeys the same laws.
D obeys no common law.
37 The passage mentions all of the following factors for the existence of life EXCEPT
A the right amount of atmosphere.
B a steady supply of water.
C steady heat and light.
D the right distance from the sun.
38 Which of the following statements is INCORRECT?
A Astronomers believe that the universe is built of the same matter.
B Proper conditions are essential to the existence of life.
C Double stars can provide steady light and heat.
D Astronomers believe that other solar systems are similar in structure to ours.
39 What kind of planet elsewhere in the universe can support life?
A Those double stars' planets.
B Those planets much hotter than our earth.
C Those planets similar to the earth.
D Those planets very close to their suns.
40 At the end of the passage the author suggests that
A it is impossible for life to exist on other planets.
B earthlike life could only exist on a few planets.
C life could exist on only one planet in a million.
D life could exist on a great number of planets.
The value of childhood is easily blurred （变得模糊不清） in today's world. Consider some recent developments: The child-murderers in the Jonesboro, Ark. schoolyard shooting case were convicted and sentenced. Two boys, 7 and 8, were charged in the murder of an 11-year-old girl in Chicago.
Children who commit horrible crimes appear to act of their own will. Yet, as legal proceedings in Jonesboro showed, the one boy who was able to address the court couldn't begin to explain his acts, though he tried to apologize. There may have been a motive —— youthful jealousy （妒忌） and resentment. But a deeper question remains: Why did these boys and others in similar trouble apparently lack any inner, moral restraint?
That question echoes for the accused in Chicago, young as they are. They wanted the girl's bicycle, a selfish impulse common enough among kids.
Redemption （拯救） is a practical necessity. How can value be restored to young lives distorted （扭曲） by acts of violence? The boys in Jonesboro and in Chicago will be confined in institutions for a relatively short time. Despite horror at what was done, children cannot be —— dealt with as adults, not if a people wants to consider itself civilized. That's why politicians' cries for adult treatment of youthful criminals ultimately miss the point.
But the moral void （真空） that invites violence has many sources. Family instability （不稳定） contributes. So does economic stress. That void, however, can be filled. The work starts with parents, who have to ask themselves whether they're doing enough to give their children a firm sense of right and wrong. Are they really monitoring their activities and their developing processes of thought?
Schools, too, have a role in building character. So do youth organizations. So do law enforcement agencies, which can do more to inform the young about laws, their meaning, and their observance （遵守）.
The goal, ultimately, is to allow all children a normal passage from childhood to adulthood （成年）, so that tragic gaps in moral judgement are less likely to occur. The relative few who fill such gaps with acts of violence hint at many others who don't go that far, but who lack the moral foundations childhood should provide —— and which progressive human society relies on.
41 The two boys in Chicago were
42 The boys in Jonesboro and Chicago apparently lacked a sense of
A right and wrong.
43 According to politicians, when children commit crimes, they should be treated in the same way as
44 Which of the following does the writer cite as a source of moral void?
A Official corruption.
B Social injustice.
C Family instability.
D Racial discrimination
45 Which of the statements is NOT true according to this passage?
A Parents should strengthen moral instruction.
B Schools should help create a moral sense in children.
C Law enforcement agencies should do more to help children understand laws.
D Youth organizations play no role in building character.
31. A 32. D 33. B 34. B 35. C
36. C 37. B 38. C 39. C 40. D
41. C 42. B 43. D 44. C 45. D