Question

【题目】They failed to finish the project in time. I regretted _________ them.

A. to be not able to help B. being not able to help

C. not being able to help D. not be able to help

Answer 1

【答案】C

【解析】考查动名词。 regret doing "遗憾做了某事" 跟动名词；regret to do sth.遗憾地去做某事。句意：他们没有按时完成项目,我非常遗憾没能帮上他们的忙。动名词的否定形式 not doing
所以选C。