—Who has taken my pen away? —. He was here a moment ago.A. It must be Li PingB. It is Li P

问题补充：

—Who has taken my pen away?

—. He was here a moment ago.

A. It must be Li Ping

B. It is Li Ping take

C. Li Ping is

D. Li Ping must take

答案：

(答案→)A. It must be Li Ping

B. It is Li Ping take

C. Li Ping is

D. Li Ping must take

解析：本题是对情态动词的考查。句意表示肯定的推测用must，而it指问句中提到的who。