Passage Four?

　　Questions 36 to 40 are based on the following passage:

　　The nuclear age in which the human race is living, and may soon be dying, began for the general public with the dropping of an atom bomb on Hiroshima on 6 August 1945. But for nuclear scientists and for certain American authorities, it had been known for some time that such a weapon was possible.?

　　An atom consists of a tiny core called the "nucleus" with attendant electrons circling round it. The hydrogen atom, which is the simplest and lightest, has only one electron. Heavier atoms have more and more as they go up the scale. The first discovery that had to do with what goes on in nuclei was radioactivity, which is caused by particles being shot out of the nucleus. It was known that a great deal of energy is locked up in the nucleus, but until just before the outbreak of the Second World War, there was no way of releasing this energy in any large quantity. A revolutionary discovery was that, in certain circumstances, mass can be transformed into energy in accordance with Einstein′s formula which states that the energy generated is equal to the mass lost multiplied by the square of the velocity of light.?

　　The A-bomb, however, used a different process, depending upon radioactivity. In this process, called "fission", a heavier atomsplits into two lighter atoms. In general, in radioactive substances this fission proceeds at a constant rate which is slow where substances occurring in nature are concerned. But there is one form of uranium called "U235" which, when it is pure, sets up cet6w.com which spreads like fire, though with enormously greater rapidity. It is this substance that was used in making the atom bomb.?

　　The political background of the atomic scientists′ work was the determination to defeat the Nazis. It was held—I think rightly—that a Nazi victory would be an appalling disaster. It was also held, in Western countries, that German scientists must be well advanced towards making an A-bomb, and that if they succeeded before the West did they would probably win the war. When the war was over,it was discovered, to the complete astonishment of both American and cet6w.com, that the Germans were nowhere near success, and, as everybody knows, the Germans were defeated before any nuclear weapon had been made. But I do not think that nuclear scientists of the West can be blamed for thinking the work urgent and necessary. Even Einstein favored it.?

　　When, however, the German war was finished, the great majority of those scientists who had collaborated towards making the A-bomb considered that it should not be used against the Japanese,who were already on the verge (邊緣) of defeat and, in any case,did not constitute such a menace to the world as Hitler. Many of them made urgent represent ations to the American Government advocating that, instead of using the bomb as a weapon of war, they should after a public announcement, explode it in a desert, and that future control of nuclear energy should be placed in the hands of an international authority. Seven of the most eminent of nuclear scientists drew up what is known as "The Franck Report" which they presented to the Secretary of War in June 1945. This is a very admirable and far-seeing document, and if it had won the assent of the politicians, none of our subsequent terrors would have arisen.?

　　36. We may infer that the writer′s attitude towards the A bomb is that .?

　　A) it is a necessary evil?

　　B) it is a terrible threat to the whole of mankind?

　　C) it played a vital part in defeating the Japanese?

　　D) it was a wonderful invention

　　37. According to the passage, an atom is heavy if .?

　　A) it has a large nucleus B) it is radioactive?

　　C) its nucleus has many electrons D) its nucleus shoots out many particles

　　38. The American and cet6w.com were astonished at the end of the Second World War against Germany because .?

　　A)the Germans had been defeated without the use of nuclear weapons?

　　B)the Western countries had won before they had invented nuclear weapons?

　　C) they thought the Germans would probably win the war?

　　D)the Germans had made little progress in developing nuclear weapons

　　39. According to the writer, most scientists who had helped in making the A bomb considered that it should not be used against the Japanese because . ?

　　A) it was such a dangerous weapon?

　　B) its use against the Japanese, was unnecessary?

　　C) it was a very inhumane weapon?

　　D) the German war was finished?

　　40.It is implied that the nuclear scientists .?

　　A)might not have agreed to develop the bomb if there had been no Nazi threat

　　B) would have developed the bomb even without the Nazi threat?

　　C)would have made the bomb, under peace?time conditions, but only for the use of an international authority?

　　D)developed the bomb because Einstein thought it urgent and necessary

　　36. 文章第一段第一句講到：人類現(xiàn)在正生活在核時代里，而且也許很快就會死在這一時代。文章最后一段最后一句也講到：如果七位最杰出的核科學(xué)家提出的報告能夠得到政治家們的同意，我們今后就不必再恐懼了。由此可推斷出作者對原子彈的態(tài)度應(yīng)與選項B)相符。

　　37. 文章第二段第一句至第三句講到：原子是由一個極小的叫做“核”的中心物質(zhì)以及繞核運動著的電子組成的。氫原子只有一個電子，是最簡單、最輕的原子。原子越重，電子就越多。由此可判斷出選項C)為正確答案。?

　　38. 文章第四段第四句講到：二戰(zhàn)結(jié)束后，英美兩國科學(xué)家驚訝地發(fā)現(xiàn)德國人根本沒有成功研制出核武器，因此，正確答案為D)。

　　39. 文章第五段第一句講到：對德戰(zhàn)爭結(jié)束后，絕大多數(shù)參與研制原子彈的科學(xué)家都認(rèn)為不該把它用來對付日本人，因為他們已處在戰(zhàn)敗的邊緣，不像希特勒那樣對世界構(gòu)成威脅。因此，正確答案為B)。

　　40. 從文章第四段可以看出研制原子彈的政治背景是為了打敗納粹，所以，選項為正確答案。