I did not attend the lecture by jackson,I ____ but I ___ all this moming

题目

I did not attend the lecture by jackson,I ____ but I ___ all this moming
A would have ,washed B could have,been washing C would have ,been watching D could have,had washing

答案

这题选C
我没有出席杰克逊的演讲,我应该去但是我上午都在洗衣服.
表示与过去相反,用would/could/might/should +动词原形,后面all this moming强调一直都在干某事,而不是干了某事而不能去,所以be doing形式表示一直持续的事情.因为前面是虚拟语气,所以要用be的完成时,所以选C