The number of deaths from heart disease will be reduced greatly if people________to eat

more fruit and vegetables.[ ]

A．persuade  

B．will persuade

C．be persuaded 

D．are persuaded

有如下程序：
main()
int x=23；
do
printf("%d",x--);
while(!x);

程序运行后的输出结果是( )。

A) 321
B) 23
C) 不输出任何内容
D) 陷入死循环