【题目】I remembered _____ the door before I left the office, but forgot to turn off the lights.
A. locking B. to lock C. having locked D. to have locked
在线课程【答案】B
【解析】考查非谓语动词。ACD三个选项都表示动作已经完成。只有B选项表示尚未做。句意：我记得离开办公室前要锁门的，但是却忘记了要关灯。remember doing="remember" having dong="remember" to have done.