If the green light isn’t on a minute.A. waitingB. to waitC. waitedD. wait

问题补充：

If the green light isn’t on, a minute.

A. waiting

B. to wait

C. waited

D. wait

答案：

A. waiting

B. to wait

C. waited

(答案→)D. wait

解析： 本题是一个要求或命令的祈使句，祈使句通常以动词原形开头，故选D。