The teachers often tell their pupils across the road when the traffic light is red. A. n

问题补充：

The teachers often tell their pupils across the road when the traffic light is red.

A. not go

B. not to go

C. don’t go

D. didn’t go

答案：

A. not go

B. not to go

C. don’t go

D. didn’t go

解析：考查动词用法。句意 老师经常告诉学生当红灯时不要过马路。考查tell的用法。 Tell sb not to do 告诉某人不要做某事。Tell后也可跟宾语从句，their pupils mustn’t across the road when the traffic light is red，这时应用mustn’t故C项错误。因此选B项。