单选题 Mary regretted ______ to John's birthday party last Sunday.
A. not going B. not to go
C. not having been going D. not to be going

【正确答案】 A
【答案解析】[解析] regret后面要跟动名词做宾语，动名词的否定式是在动名词之前直接加not。本句的意思是：“玛丽后悔上个星期天没有去参加约翰的生日晚会。”