On reaching home I discovered that...-环球网校

单选题

On reaching home I discovered that I ____ my keys at the office.

left

have left

was left

had left

查看答案

正确答案:D

【解析】考察时态问题。leave my keys at the office（把钥匙落在办公室）这个动作发生在discover（发现）之前，discover为过去式，那么leave应该为过去完成时态（过去的过去），所以应为had left，故答案选D。

【题意】一到家我才发现我把钥匙落在办公室了。