After he was elected _______ Chairman of _______ Workers’ Union, he began to concentrate on helping ______ unemployed.

A．/; the; the

B．/; the; /

C．the; /; the

D．/; /; the

如果用户下班要离开计算机，在Windows的关闭系统选项中可选择______。

A．待机(S)

B．关闭(U)

C．切换到MS—DOS方式

D．重新启动(R)