第34题: [单项选择]They failed to pass the exam last time. I regretted ______. A. being unable to help B. to be not able to help C. being not able to help D. not be able to help 参考答案:A 答案解析:本题为语法结构题。regret doing sth 表示“后悔做过了某件事”,而 regret to do sth 表示“不想去做某件事”。另外,否定词 not 应该放在动名词和动词不定式之前,即 n