企源知识库

I remembered that the air conditioners _____ turned off before I left home.
A、were
B、were to be
C、had been
D、have been
【正确答案】：C
【题目解析】：考查动词的时态。句意：我记得在离开家之前空调已经关上了。turn off的动作发生在left home之前，因此要用过去完成时态。