The policeman the traffic to move forward after the traffic light turns green.
A. leads to
B. signals to
C. asks for
D. informs of
网友回答
A. leads to
(答案→)B. signals to
C. asks for
D. informs of
解析：signal to意为“给……发信号；示意”；lead to意为“导致”；ask for意为“请求”；inform of意为“通知；告诉”。