Don’t forget all the lights when you leave the classroom.
A. to turn off
B. turning off
C. turn on
D. turning on
网友回答
(答案→)A. to turn off
B. turning off
C. turn on
D. turning on
解析：考查forget的用法，forget to do 意为忘记去干某事 forget doing 忘记做过某事
句意为，不要忘记去关掉所有的灯，当你离开教室的时候。