All lights after the students left the classroom.
A. went down
B. goes off
C. goes down
D. went off
网友回答
A. went down
B. goes off
C. goes down
(答案→)D. went off
解析：go down表示停止，被接受，沉下，被打败的意思，而go off表示离开，消失，变差，熄火的意思，所有的灯都熄灭，所以将go down和went down，排除，又根据时间状语after the students left the classroom.可知答案为一般过去时，故选D