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问题 单项选择题 A1型题

* * 镜的最大放大倍数为（）

A.10倍

B.20倍

C.40倍

D.200倍

E.400倍

答案

参考答案：C

解析：目前临床使用的 * * 镜放大倍数为20～40倍。

单项选择题

用于润滑各种重负荷齿轮的润滑油是（）。

A、机械油

B、内燃机油

C、齿轮油

D、液压传动油
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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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