I should have come to the movie, but I ______ too busy.(A) was (B) were (C) had been (D) am

题目

I should have come to the movie, but I ______ too busy.(A) was (B) were (C) had been (D) am
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答案

选A.
should have done s.th是指本应该做什么但没做,
属于虚拟语气,是对过去的假设.因此选我当时很忙,就是过去时was.
100%对