可以粘贴复制的word版本 剑桥雅思真题 8 test3演示教学文档格式.docx

1、We can cause the lightning to strike where we want it to using rockets, says Ralph Bernstein, manager of lightning projects at EPRI. The rocket site is providing precise measurements of lightning voltages and allowing engineers to check how electrical equipment bears up.Bad behaviourBut while rocket

2、s are fine for research, they cannot provide the protection from lightning strikes that everyone is looking for. The rockets cost around $1,200 each, can only be fired at a limited frequency and their failure rate is about 40 per cent. And even when they do trigger lightning, things still do not alw

3、ays go according to plan. Lightning is not perfectly well behaved, says Bernstein. Occasionally, it will take a branch and go someplace it wasnt supposed to go.And anyway, who would want to fire streams of rockets in a populated area? What goes up must come down, points out Jean-Claude Diels of the

4、University of New Mexico. Diels is leading a project, which is backed by EPRL to try to use lasers to discharge lightning safely- and safety is a basic requirement since no one wants to put themselves or their expensive equipment at risk. With around $500,000 invested so far, a promising system is j

5、ust emerging from the laboratory.The idea began some 20 years ago, when high-powered lasers were revealing their ability to extract electrons out of atoms and create ions. If a laser could generate a line of ionisation in the air all the way up to a storm cloud, this conducting path could be used to

6、 guide lightning to Earth, before the electric field becomes strong enough to break down the air in an uncontrollable surge. To stop the laser itself being struck, it would not be pointed straight at the clouds. Instead it would be directed at a mirror, and from there into the sky. The mirror would

7、be protected by placing lightning conductors close by. Ideally, the cloud-zapper （gun） would be cheap enough to be installed around all key power installations, and portable enough to be taken to international sporting events to beam up at brewing storm clouds.A stumbling blockHowever, there is stil

8、l a big stumbling block. The laser is no nifty portable: its a monster that takes up a whole room. Diels is trying to cut down the size and says that a laser around the size of a small table is in the offing. He plans to test this more manageable system on live thunderclouds next summer.Bernstein sa

9、ys that Dielss system is attracting lots of interest from the power companies. But they have not yet come up with the $5 million that EPRI says will be needed to develop a commercial system, by making the lasers yet smaller and cheaper. I cannot say I have money yet, but Im working on it, says Berns

10、tein. He reckons that the forthcoming field tests will be the turning point - and hes hoping for good news. Bernstein predicts an avalanche of interest and support if all goes well. He expects to see cloud-zappers eventually costing $50,000 to $100,000 each.Other scientists could also benefit. With

11、a lightning switch at their fingertips, materials scientists could find out what happens when mighty currents meet matter. Diels also hopes to see the birth of interactive meteorology - not just forecasting the weather but controlling it. If we could discharge clouds, we might affect the weather, he

12、 says.And perhaps, says Diels, well be able to confront some other meteorological menaces. We think we could prevent hail by inducing lightning, he says. Thunder, the shock wave that comes from a lightning flash, is thought to be the trigger for the torrential rain that is typical of storms. A laser

13、 thunder factory could shake the moisture out of clouds, perhaps preventing the formation of the giant hailstones that threaten crops. With luck, as the storm clouds gather this winter, laser-toting researchers could, for the first time, strike back.Questions 1-3Choose the correct letter, A, B, C or

14、 D.Write the correct letter in boxes 1-3 on your answer sheet.1 The main topic discussed in the text isA the damage caused to US golf courses and golf players by lightning strikes.B the effect of lightning on power supplies in the US and in Japan.C a variety of methods used in trying to control ligh

15、tning strikes.D a laser technique used in trying to control lightning strikes.2 According to the text, every year lightningA does considerable damage to buildings during thunderstorms.B kills or injures mainly golfers in the United States.C kills or injures around 500 people throughout the world.D d

16、amages more than 100 American power companies.3 Researchers at the University of Florida and at the University of New MexicoA receive funds from the same source.B are using the same techniques.C are employed by commercial companies.D are in opposition to each other.Questions 4-6Complete the sentence

17、s below.Choose NO MORE THAN TWO WORDS from the passage for each answer.Write your answers in boxes 4-6 on your answer sheet.4 EPRI receives financial support from.5 The advantage of the technique being developed by Diels is that it can be used.6 The main difficulty associated with using the laser eq

18、uipment is related to its.Questions 7-10Complete the summary using the list of words, A-l, below.Write the correct letter, A-l, in boxes 7-10 on your answer sheet.In this method, a laser is used to create a line of ionisation by removing electronsfrom 7.This laser is then directed at 8.in order toco

19、ntrol electrical charges, a method which is less dangerous than using9.As a protection for the lasers, the beams are aimed firstly at10.A cloud-zappers B atoms C storm cloudsD mirrors E technique F ionsG rockets H conductors I thunderQuestions 11-13Do the following statements agree with the informat

20、ion given in Reading Passage 1?In boxes 11-13 on your answer sheet writeYES if the statement agrees with the claims of the writerNO if the statement contradicts the claims of the writerNOT GIVEN if it is impossible to say what the writer thinks about this11 Power companies have given Diels enough mo

21、ney to develop his laser.12 Obtaining money to improve the lasers will depend on tests in real storms.13 Weather forecasters are intensely interested in Dielss system.READING PASSAGE 2You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 below.The Nature of Geniu

22、sThere has always been an interest in geniuses and prodigies. The word genius, from the Latin gens （= family） and the term , meaning begetter, comes from the early Roman cult of a divinity as the head of the family. In its earliest form, genius was concerned with the ability of the head of the famil

23、y, the paterfamilias, to perpetuate himself. Gradually, genius came to represent a persons characteristics and thence an individuals highest attributes derived from his or guiding spirit. Today, people still look to stars or genes, astrology or genetics, in the hope of finding the source of exceptio

24、nal abilities or personal characteristics.The concept of genius and of gifts has become part of our folk culture, and attitudes are ambivalent towards them. We envy the gifted and mistrust them. In the mythology of giftedness, it is popularly believed that if people are talented in one area, they mu

25、st be defective in another, that intellectuals are impractical, that prodigies burn too brightly too soon and burn out, that gifted people are eccentric, that they are physical weaklings, that theres a thin line between genius and madness, that genius runs in families, that the gifted are so clever

26、they dont need special help, that giftedness is the same as having a high IQ, that some races are more intelligent or musical or mathematical than others, that genius goes unrecognised and unrewarded, that adversity makes men wise or that people with gifts have a responsibility to use them. Language has been enriched with such terms as highbrow, eggheadblue-stockingwiseacreknow-allboffin and, for many, intellectual is a term of denigration.The nineteenth century saw considerable interest in