I ________ my key to my office at home, so I had to wait until other teachers ________ to open the door.
A.had left; came
B.left; came
C.has left; came
D.left; would e
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A解析本题考查过去完成时和一般过去时的比较。leave my key这个动作明显发生在had to wait之前,所以为过去的过去,用过去完成时;而e这个动作是出现在until引起的时间状语从句中,应该用一般过去时代替过去将来时,所以