--Hurry up! The bus is ing.
--Wait a minute. Don’t cross the street the traffic lights are green.
A. until
B. after
C. while
D. since
网友回答
(答案→)A. until
B. after
C. while
D. since
解析：until直到；after在……之后；while然而，当……时；since由于，自从……以来。句意：快点，公交车来了。——等一下，到绿灯亮时，再过街。结合语境可知选A。