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在1标准大气压下，酒精和水的沸点分别是78℃和100℃，把它们分别装在两只试管中，再放在不断加热的沸水中。那么，这两只试管中的会沸腾的是        。

答案

酒精

题目分析：（1）在温度达到了水的沸点100℃的沸水中，水的温度保持不变；试管中的水从烧杯中吸热，温度达到水的沸点后，就和烧杯中的水的温度一样，就不能从烧杯中继续吸热，这时虽然达到了水的沸点100℃，但不能吸收热量，所以不会沸腾．

（2）装有酒精试管，水沸腾后温度保持不变．但由于酒精的沸点78℃，低于水的沸点，当试管中的酒精达到酒精的沸点，但仍能从沸水中吸热，所以会沸腾．

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1.Passage 1
下面你将听到联合国秘书长接受有关奖项的一段讲话。
Mr. Chairman, Excellencies, Ladies and Gentlemen,
I should like, first of all, to once again thank the Norwegian Nobel Committee for the award they have made to the United Nations Peace-Keeping Operations. Their decision has been acclaimed all over the world. I take this opportunity also to express once again my deep gratitude to the countries, which have contributed troops or provided logistical support to these operations. It is to their willing cooperation that we owe the success of this great experiment in conflict control.
Peace—the word evokes the simplest and most cherished dream of humanity. Peace is, and has always been, the ultimate human aspiration. And yet our history shows that while we speak incessantly of peace, our actions tell a very different story. Peace is an easy word to say in any language. As Secretary-General of the United Nations, I hear it so frequently from so many different mouths and different sources, that it sometimes seems to me to be a general incantation more or less deprived of practical meaning.
What do we really mean by peace Human nature being what it is, peace must inevitably be a relative condition. The essence of life is struggle and competition, and to the extent perfect peace is an almost meaningless abstraction. Struggle and competition arc stimulating, but when they degenerate into conflict they are usually both destructive and disruptive. The aim of political institutions like the UN is to draw the line between struggle and conflict and to make it possible for nations to stay on the right side of the line. Peace-keeping operations are one very practical means of doing this.
What we are trying to create in the UN is a world where nations recognize at the same time the ultimate futility of war and the collective responsibility that men and women everywhere share for ensuring a decent future. All human experience seems to show that in international, as in national, affairs, rule of law is an essential objective for any society wishing to survive in reasonable conditions. We now recognize that all humanity—the whole population of this planet—has in many respects become, through the revolutionary force of technological and other changes, a single society. The evolution of international law and international authority may well be decisive in determining whether this global society is going to survive in reasonable conditions.
In a larger perspective, we must work towards a time when war will cease to be an acceptable option of national policy or a possible means of settling disputes, and when a reliable international system will take its place. From this perspective, the development of international peace-keeping has an essential place, just as the concept of a civil police was essential to the development of rule of law within nation states. I hope that the attention now being given to peace-keeping, which is symbolized by the award of the Nobel Peace Prize, will not only strengthen our capacity to conduct the affairs of nations but also stimulate a wider effort to consider the new means and the new institutions needed to ensure a better common future. Thank you.
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试述变频式空调器的工作原来及产品特点。
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