问题
选择题
The policeman asked the child ________ cross the street ________ the traffic lights turned green.
A．not, when
B．not to, until
C．didn't, before
D．not to, after
答案
答案：B
题目分析：句意：警察让这个小孩等到交通灯变绿才可以过马路。Ask sb to do sth“让某人做某事”，否定形式：ask sb not to do sth。Not…until“直到……时候才”，结合语境，故选B。