Zhang Yimou, the director of Hero and House of Flying Daggers,         on Sunday that he has two sons and a daughter with his wife, Chen Ting.

A．foresaw

B．teased

C．appointed

D．exposed

以下对于窗位概念的描述，正确的是（）

A.窗位相当于显示灰阶的中心

B.不同机器的窗位值不同

C.窗位规定所显示CT值的范围

D.窗位与所显示的组织CT值无关

E.通常窗位选择以水的CT值为标准