—Where is _______ key to the door, Jim?
—It's in my pocket. [ ]
A. a
B. the
C. ×
答案:B
具透疹作用、药性偏温者有()。
显示器所表现的亮度信号的等级差别称为
A.CT值标度B.灰阶C.窗宽D.窗位E.矩阵