—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
网友回答
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。