–Tom you didn’t come to my party last night?– I but my mom hurt her back and I had to l

问题补充：

–Tom, you didn’t come to my party last night?

– I , but my mom hurt her back and I had to look after her.

A. had to

B. didn’t

C. wouldn’t

D. was going to

答案：

A. had to

B. didn’t

C. wouldn’t

(答案→)D. was going to

解析：

由下面的but可知是妈妈背受伤了要照顾，本来是打算去了，可知Ｄ正确。be going to do 表示计划或打算做某事，此时用过去时was。