关于单词regret的用法```

题目

关于单词regret的用法```
They failed to pass the exam last time.I regretted ____ them.
A to be not able to help
B being not able to help
C not being ablt to help
D not be able to help
(我看不出BC有什么区别,希望高手给出正确答案和解析,

答案

此题应选“C”.这里要注意“be able to ”是个固定短语“能够”的意思,且not 一般用在动词之前起否定作用,故选“C”请看以下例句：I bitterly regret that we have not been able to do better.我们没能做得更好一些...