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问题 解答题

先化简，再求值：5x2-[3x-2（2x-3）+7x2]，其中x=1．

答案

原式=5x2-3x+4x-6-7x2=-2x2+x-6，

当x=1时，原式=-2+1-6=-7．

单项选择题

( )是指导项目管理工作的纲领性文件。

A．项目管理规划
B．建设工程项目设计规划
C．建设工程设计管理规划
D．建设工程项目管理规划
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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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