—The patient looks much better.________ is it that has made him ________ he is today?

—Perhaps the special medicine and his family's patient care.

A．What；that

B．That；that

C．What；what

D．What；which

若一个栈以向量V[1..n]存储，初始栈顶指针top为n+1，则下面x进栈的正确操作是( )。

A．top=top+1; V[top]=x
B．V[top]=x; top=top+1
C．top=top-1; V[top]=x
D．V[top]=x; top=top-1