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问题 单项选择题

以下有关特征X射线的描述，错误的是（）

A.电子与靶原子内层轨道电子作用的结果

B.是连续能量的X射线

C.反映了原子内部的壳层结构

D.光子能量小于入射电子能量

E.发生几率与靶原子序数有关

答案

参考答案：B

选择题

Only lately        about the dark secrets behind the seemingly-happy marriage of the golf star Tiger Woods.[ ]

A. the public have known

B. were the public known

C. have the public known

D. the public knewks
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选择题

Mr. Zhang is ________ taking an airplane. He has to go to Beijing by train. [ ]

A. afraid of

B. fond of

C. short of

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