26. (2018乐山)Tom, please remember ________ the lights when you leave.
A. turn off  B. turning off  C. to turn off
26. C【解析】考查动词不定式。句意：汤姆，当你离开时，请记得关灯。remember to do sth.记住要去做某事(未做)；remember doing sth.记得做过某事(已做)。根据句意可知，汤姆还没有离开，所以关灯这件事还没有做。故选C。