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问题 单项选择题

假设数据库性能用“开销”，即时间、空间及可能的费用来衡量，则在数据库应用系统生存期中存在很多种开销。其中，对物理设计者来说，主要考虑的是______。

A．规划开销

B．设计开销

C．操作开销

D．运行维护开销

答案

参考答案：C

选择题

下列可用来区别SO2和CO2气体的是（   ）

①澄清的石灰水②氢硫酸③氯水④酸性高锰酸钾⑤氯化钡⑥品红溶液

A．①④⑤⑥

B．②③④⑤

C．①②③⑥

D．②③④⑥
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填空题

Beijing: The United States and North Korea had their first ______ in four months here this afternoon as part of the ______ negotiations on how to end North Korea’s nuclear program, but diplomats played down prospects for______. James A. Kelly, assistant ______, and Kim Yong Ⅱ, North Korea’s deputy foreign minister, met ______ of formal discussions, ______ on direct dialogue that began after a stormy meeting ______ in which North Korea warned that it was moving quickly to ______ nuclear arms. The Bush administration had insisted ______ that it would only hold talks with North Korea ______ because, it argued, only ______ pressure would persuade North Korea to______. It got its way when North Korea dropped its insistence on ______ and agreed, after extensive efforts by China, to hold unusual simultaneous negotiations with ______,______,______ and ______ as well as the United States. Though Bush administration officials had not ______ talking privately with the North Koreans during______, the fact that Mr. Kelly and Mr. Kim met on the first day was seen as a sign of ______ by the American side.
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