— David, look at the man in white over there. Can you tell me _____?

— He is a doctor. [ ]

A. Who is he

B. who he is

C. what is he

D. what he is

下列选项中不属于结构化程序设计原则的是______。

A．可封装
B．自顶向下
C．模块化
D．逐步求精