调焦的目的是调整镜头到()的距离,在胶片上得到鲜明锐利的
A、被摄体
B、影像
C、焦点
D、后节点
参考答案:B
The _______________ Sunday in May is Mother's Day. [ ]
A. first
B. second
C. third
What’s true about, the visiting hours of the hospital().
A.Hospital visiting hours begin at 10: 00.
B.Visitors must leave before 10: 00.
C.Visitors can come and leave at any time.