问题补充:
Hurry up. The car is coming.
Wait a minute, Don’t cross the street the traffic lights are green.
A. while
B. when
C. until
D. after
答案:
A. while
B. when
(答案→)C. until
D. after
解析:while虽然,当……时;when既然,当……时;until直到;after在……之后。句意:快点,车来了。——等一下,直到绿灯亮时再穿过马路。结合语境可知选C。