Seeing the man on the bike with a boy at the front and the other at the back the policema

问题补充：

Seeing the man on the bike with a boy at the front and the other at the back, the policeman signed stop.

A. to the man

B. to the man to

C. for the man for

D. to the man for

答案：

A. to the man

(答案→)B. to the man to

C. for the man for

D. to the man for

解析：本题考查动词及非谓语动词。句中sign to sb表示“向某人示意”；第二个不定式to stop表示目的性。即警察示意那个人停下来。故选B。