第3部分：概括大意与完成句子  (第23～30题，每题1分，共8分)
　　阅读下面这篇短文，短文后有2项测试任务：(1)第23~26题要求从所给的6个选项中为第3～6段每段选择1个正确的小标题；(2)第27~30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。请将答案涂在答题卡相应的位置上。
　　Electromagnetic Energy
　 　1．White light seems to be a combination of all colors．The energy that comes from a source of light is not limited to the kind of energy you can see．Heat is given off by a flame or an electric light．On a cloudy day it is possible to get a sunburn even though you feel coo1．Visible light and the kinds of energy that produce warmth and sunburn are examples electromagnetic energy．
　　2．The sun is 93 million miles from the earth．Yet we can use energy from the sun because electromagnetic energy travels through space.
　　3．Many other kinds of energy are also types of electromagnetic energy．Radio，television，and radar signals travel from transmitters to receivers as low-energy electromagnetic waves . Intrared(红外线的)radiation is an electromagnetic wave．When it is absorbed by matter，heat is produced.Waves of infrared and visible light have more energy than waves of radio，television，or radar．Ultraviolet rays(紫外线)and，X-rays are electromagnetic waves with even greater amounts of energy . Infrared radiation is used in cooking food and heating buildings . Sunlight and electric lights are part of our requirements for normal living．Ultraviolet radiation is useful in killing certain disease organisms．X-rays and gamma rays have so much energy that they travel right through solid objects．They can be used to detect and treat cancer．X-rays are used in industry to find hidden cracks in metal，and in medicine to reveal broken bones．
　　4． Usually we use electricity to generate electromagnetic energy．The source of most of our energy is the sun．Heat from the sun causes water to evaporate．When the water falls to the earth as rain，some of it is trapped behind dams and then used to operate electric generators．Other generators are powered by coal，but the energy stored in coal came from the sun．too．
　　5．  Until recently,the source of the tremendous amount of energy given off by the sun was a puzzle．If the sun depended on chemical reactions，it would have used up all its energy long ago．Experiments with electromagnetic radiation led to the theory that mass can be converted into energy．About forty years after the theory was proposed，nuclear energy was harnessed(利用)by man．Chemical energy comes from electron(电子) rearrangement. Nuclear energy comes from a change in the nucleus of an atom．Compared with chemical reactions．nuclear reactions release millions of times more energy per pound of mel．We now believe that the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium (氦)．
　　6．  Nuclear energy is beginning to compete with coal as an economical source of power to generate electricity．It is also being used to operate engines in large ships．Scientists continue to seek new and better methods of obtaining and using energy.
　　23 Paragraph 3
　　24 Paragraph 4
　　25 Paragraph 5
　　26 Paragraph 6
　　A Nuclear Reactions as the Lasting Source of the Sun's Energy
　　B The Most lmportant Source of Energy
　　C Types of Electromagnetic Energy
　　D The Machines Used for Energy Generation
　　E Seeking New Sources of Energy
　　F The Use of Ultraviolet Radiation in Medicine
　　27 One can get a sunburn even                  .
　　28 Infrared radiation can produce heat             .
　　29 X-rays and gamma rays can be used to detect and
　　treat cancer        .
　　30 Chemical energy is generated          .
　　A when it is absorbed by matter
　　B when it is cloudy
　　C because they can pass through solid objects
　　D when the sunrays are fierce
　　E when a change in the nucleus of an atom takes place
　　F when electron rearrangement takes place
　　第4部分：阅读理解（第31~45题，每题3分，共45分）
　　下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案涂在答题卡相应的位置上。
　　第一篇       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 saIt 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, beeause some of it is in the fonn of icebergs(冰山)and glaciers (冰川)．Even worse,some of it has been po1luted．
At the moment，this small amount of flesh water is still enough for us.Howeve，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 eriect on alriculture and industry．
　 　In addition to stopping wasting our precious water,one useful step we shouId take is to develop ways of reusing it . Experiments have alre．ady been done in this field，but only on a small scale．
　　Today, in most large cities，water is used only once and it eventually retums 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 flesh from a spring．
　　But even if every large city purified and reused its water，we still would not have enougn.Where could we tum 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 a11 these steps，we'11 be in no danger of drying up !
　　31 The phrase''the world"in the first line of the passage refers to
　　A  "man"．
　　B  "you"．
　　C  "woman"．
　　D  "they"．
　　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   Lessthan 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 flesh as spring water．
　　D  Oceans are the largest water source．
　　35 According to the passage，sea-water can be turned into flesh water by
　　A heating it up．
　　B treating it with chemicals．
　　C taking salt out of it．
　　D drying it up.