题目内容
Some polls show that roughly two-thirds of the general public believe that elderly Americans are______by social isolation and loneliness.(北京大学2006年试题)
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The misfortunes of human beings may be divided into two classes: First, those inflicted by the non-human environment and, second, those inflicted by other people. As mankind has progressed in knowledge and technique, the second class has become a continually increasing percentage of the total. In old times, famine, for example, was due to natural causes, and although people did their best to combat it, large numbers of them died of starvation. At the present moment large parts of the world are faced with the threat of famine, but although natural causes have contributed to the situation , the principal causes are human. For six years the civilized nations of the world devoted all their best energies to killing each other, and they find it difficult suddenly to switch over to keeping each other alive. Having destroyed harvests, dismantled agricultural machinery, and disorganized skipping , they find it no easy matter to relieve the shortage of crops in one place by means of a superabundance in another, as would easily be done if the economic system were in normal working order. As this illustration shows, it is now man that is man"s worst enemy. Nature, it is true, still sees to it that we are mortal, but with the progress in medicine it will become more and more common for people to live until they have had their fill of life. We are supposed to wish to live forever and to look forward to the unending joys of heaven, of which, by miracle, the monotony will never grow stale. But in fact, if you question any candid person who is no longer young, he is very likely to tell you that, having tasted life in this world, he has no wish to begin again as a "new boy" in another. For the future, therefore, it may be taken that the most important evils that mankind have to consider are those which they inflict upon each other through stupidity or malevolence or both.
It is hard to tell whether we are going to have a boom in the economy or a______.(中南大学2006年试题)
The term genetically modified organism ( GMO) refers to plants, microbes and animals with genes transferred from other species in order to produce certain novel characteristics (for example resistance to pests, or herbicides) and are produced by recombinant DNA technology. Four main sources of hazards of GMO are discussed by scientists worldwide: 1) those due to the new genes, and gene products introduced; 2 ) unintended effects inherent to the technology; 3) interactions between foreign genes and host genes; and 4) those arising from the spread of the introduced genes by ordinary cross-pollination as well as by horizontal gene transfer. GM crops contain material, which is not present in them under natural conditions, and they form a part of our daily diet. To understand what effect they can have on us and on our animals, it is very important to study the influence of those GM plants in different organisms for several generations. At present, these studies are lacking from the scientific literature. Also, several detrimental effects of GM crops had been showed on the metabolism of animals. The hazard of GMO was shown for animals and the environment in many investigations. Earlier it was shown that consumption of GM food by animals led to the negative changes in their organisms. Experiments, conducted by A. Pusztai showed that potatoes modified by the insertion of the gene of snowdrop lectin (雪花莲凝集素 ), stunted the growth of rats, significantly affected some of their vital organs, including the kidneys, thymus (胸腺) , gastrocnemius muscles (腓肠肌) and others and damaged their intestines and their immune system.
Jimmy earns his living by______works of art in the museum.(中南大学2007年试题)
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