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阅读下面的文字，完成文后五题。人们对碳正离子进行研究时发现，它的“寿命”非常短，大约在10-23～10-6秒之间，因此，不能直接用仪器观测到这个有机反应中重要的中间体的“面目”。欧拉的贡献在于他发现了制备“长寿”高浓度碳正离子的方法。他采用了亲和能力小的溶剂，在低温(大约-100℃)下，可以使碳正离子具有长寿命。为了得到高浓度的碳正离子，欧拉使用一种很强的酸(被称为路易斯酸)，它可以使卤代烷生成碳正离子。欧拉的成就是建立在许多科学家辛勤工作的基础之上的。早在20世纪50年代，温斯坦在研究亲和取代反应和一些有机物重排时曾经假设，中间体碳正离子是非经典的，它包含一个5配位价的碳。1979年的诺贝尔化学奖获得者布朗对此也做过研究。但是这些仅是假设和解释而已。欧拉的大量工作证明了在强酸介质中，饱和碳氢化合物会发生质子化。通过对碳正离子的分析，能够发现低成本制造化工产品的方法，目前已有几十种产品得益于欧拉的发现。 下列语句不适合作本文标题的一项是（）。
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在工资表中，显示工资最少的3名职工记录，SQL语句为：SELECT*【 】3FROM工资表ORDER BY工资【 】。
Many theories concerning the causes of juvenile delinquency (crimes committed by young people) focus either on the individual or on society as the major contributing influence. Theories (21) on the individual suggest that children engage in criminal behavior (22) they were not sufficiently penalized for previous misdeeds or that they have learned criminal behavior through (23) with others. Theories focusing on the role of society suggest that children commit crimes in (24) to their failure to rise above their socioeconomic status, (25) as a rejection of middle-class values. Most theories of juvenile delinquency have focused on children from disadvantaged families, (26) the fact that children from wealthy homes also commit crimes. The latter may commit crimes (27) lack of adequate pa- rental control. All theories, however, are tentative and are (28) to criticism. Changes in the social structure may indirectly (29) juvenile crime rates. For example, changes in the economy that (30) to fewer job opportunities for youth and rising unemployment (31) make gainful employment increasingly difficult to obtain. The resulting discontent may in (32) lead more youths into criminal-behavior. Families have also (33) changes these years. More families consist of one-parent households or two working parents; (34) , children are likely to have less supervision at home (35) was common m the traditional family structure. 29（）
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Some weeks ago, riding in a cab from Boston to Cambridge, my driver turned and asked me what I did for a living. "Teach English," I said. "Is that so" The young man continued. "I was an English major." But then, instead of chatting idly about Joyce or dropping the subject altogether, this driver caught me short. "You guys," he said, turning back so that his furry face pressed into the glass partition, "ought to be shot." I think he meant it.The guilty party in this present state of affairs is not really the academic discipline. It is not the fault of English and philosophy and biology that engineering and accounting and computer science afford students better job opportunities and increased flexibility in career choice. Literature and an understanding of, say, man’s evolutionary past are as important as ever. They simply are no longer perceived in today’s market as salable. That is a harsh economic fact. And it is not only true in the United States. Employment prospects for liberal arts graduates in Canada, for example, are said to be the worst since the 1930s.What to do I think it would be shortsighted for colleges and universities to advise students against majoring in certain subjects that do not appear linked (at least directly) to careers. Where our energies should be directed instead is toward the development of educational programs that combine course sequences in the liberal arts with course in the viable professions. Double majors--one for enrichment, one for earning one’s bread--have never been promoted very seriously in our institutions of higher learning, mainly because liberal arts and professional-vocational faculties have long been suspicious or contemptuous of one another. Thus students have been directed to one path or the other, to the disadvantage of both students and faculty.A hopeful cue could be taken, it seems to me, from new attempts in the health profession (nursing and pharmacy, for example), where jobs are still plentiful, to give the humanities and social sciences a greater share of the curriculum. Why could not the traditional history major in the college of arts and sciences be pointed toward additional courses in the business school, or to engineering, or to physical therapy This strategy requires a new commitment from both the institution and the student and demands a much harder look at the allocation of time and resources. But in an age of adversity, double majors are one way liberal arts students can more effectively prepare for the world outside. The obstacles in course sequences in academic schooling are indicated in all of the following EXCEPT（）
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