将两个关系拼接成一个新的关系，生成的新关系中包含满足条件的元组，这种操-我要搜题网

[填空题]The advantages and disadvantages of a large population have long been a subject of discussion among economists. It has been argued that the supply of good land is limited. To feed a large population, inferior land must be{{U}} (36) {{/U}}and the good land worked{{U}} (37) {{/U}}. Thus, each person produces less and this means a{{U}} (38) {{/U}}average income than could be obtained with a smaller population. Other economists have argued that a large population gives more{{U}} (39) {{/U}}for specialization and the development of{{U}} (40) {{/U}}such as ports, roads and rail ways, which are not likely to be built unless there is a big demand to{{U}} (41) {{/U}}them. One of the difficulties in carrying out a{{U}} (42) {{/U}}birth control program lies in the fact that official attitudes to population growth{{U}} (43) {{/U}}from country to country depending on the level of industrial development and the availability of food and raw materials. In the developing country whe

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[判断题]高处作业均须先搭建脚手架、使用高空作业车、梯子、移动平台等措施，防止工作人员发生坠落。
A.正确
B.错误

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[单选题]正常肺部叩诊音为
A.鼓音
B.过清音
C.浊音
D.清音
E.实音

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[多选题]下列关于工作票的有效期与延期，正确的叙述包括( )。
A.第一、二种工作票和带电作业工作票的有效时间，以批准的检修期为限
B.第一种工作票只能延期一次
C.第二种工作票只能延期一次
D.带电作业工作票可以延期一次

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[简答题]赵某是否构成毒品犯罪的再犯

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[多项选择]关于毛发生长周期，叙述错误的有（）
A. 生长期3年
B. 退行期3个月
C. 休止期3周
D. 每天有120根头发脱落为正常脱发
E. 正常脱发的同时，有等量的头发再生

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[判断题]( )CRH2型动车组二级检修质量标准中：在绝缘测试中，主回路501C～大地间≥0.2MΩ（使用500V兆欧表）。(1.0分)
A.正确
B.错误

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[单项选择]Kodak Is Changing the Picture
In September 2003, Mr Carp, CEO of Kodak, announced what he called the "biggest taming point" in Kodak’s history. There would, he said, be no more big investments in traditional film. He also reduced the company’s dividend by 72% to finance a $3 billion investment. By 2010, Mr Carp hopes for an income of $ 20 billion. In 2002, some 70% of the company’s income came from its traditional film products, the remainder from digital. By 2006, the plan is for digital income to account for 60%.
That will take some doing. In the nine months to September 30th, 2003, Kodak’s net income rose by only 1.5% (to $9.5 billion), and despite the first profits from its digital cameras, net profits fell by 63% to $246 million. Over the next three years, Kodak expects film sales to fall by 10% or more every year in America and Europe, and by up to 20% a year in Japan.
Companies that find their business model threatened by rapid technological change often fa
A. Right
B. Wrong
C. Doesn’t Say

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[多选题]天气恶劣难以辨认信号行车的办法包括（）内容。
A.列车按地面信号显示运行时，列车调度员应及时发布调度命令，改按天气恶劣难以辨认信号的办法行车。
B.列车按机车信号的显示运行。当接近地面信号机时，司机应确认地面信号，遇地面信号与机车信号显示不一致时，应立即采取减速或停车措施。
C.当无法辨认出站（进路）信号机显示时，在列车具备发车条件后，司机凭机车信号的显示起动列车，在确认出站（进路）信号机显示正确后，再行加速。
D.天气转好时，应及时报告列车调度员发布调度命令，恢复正常行车。

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[单项选择]引起反射性呕吐的病因包括下列疾病，但除外
A. 急性胃肠炎
B. 青光眼
C. 尿毒症
D. 急性心肌梗死
E. 泌尿系结石

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[多选题] ZD6-D型电动转辙机的X2的作用是( )
A.定位启动线
B.反位启动线
C.定位表示线
D.反位表示线

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[单选题]阻拦报火警或者谎报火警给予（）处罚
A.劳动教养
B.1年以下有期徒刑
C.撤销其电话
D.警告、罚款或者10日以下拘留

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[单选题] 到( )年,我国成功实现由计划经济体制向社会主义市场经济体制的转变,社会主义市场经济体制基本框架初步建立,经济和社会发展的体制环境发生重大变化。
A. 2000
B. 2001
C. 2002
D. 2003

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[判断题]政治管理强调的是秩序和稳定，政治统治强调的是秩序和效率。

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[简答题]乐毅帅五国伐齐时，被授哪国相国印？