--Alice, why didn't you e yesterday?
--I , but I had an unexpected visitor.
A. had
B. would
C. was going to
D. did
网友回答
A. had
B. would
C. was going to
D. did
解析：当不定式在某些结构后作复合谓语时，不定式符号 to后的内容可以省略。常见的结构有：be able to，be going to，have to，ought to，used to等。