hurry up ,the bus is coming ---oh,no.we mustn't cross the street()the traffic are green.

问题描述:

hurry up ,the bus is coming ---oh,no.we mustn't cross the street()the traffic are green.
A after B since C while D until 要说为什么

D
...之前
--快点,车来了
--不,在红绿灯变绿灯之前我们不可以过马路.
A ...之后
B 因为
C 当
都不符合题意