I regret _____ hard at school,or I would have succeeded in passing the exam.选项:a、not to work b、having not worked c、to have not worked d、 not having worked 选哪个?为什么?请分析并翻译整句

regret not having worked hard at schoolI regret _____ hard at school,or I would have succeeded in passing the exam.选项:a、not to work b、having not worked c、to have not worked d、 not having worked 选D.为什么A不对?我知道regret to do I regret I will never regret i regret to tell you this,but...i regret to tell you this,but i broke the window.为什么要用but.还有一个.it's hard work climbing mountains.it's hard work后加doing I regret _____ hard at school,or I would have succeeded in passing the exam.选项:a、not to work b、having not worked c、to have not worked d、 not having worked 选哪个?为什么?请分析并翻译整句 Mary was hard at _____ when I got home. _____ a student,I must study very hard. I find it hard _____ (talk) with the old man. I study hard _____(go)to Tsinghua University. I find _____ hard ______ ______ good friends with them. I was having a hard time _____ (find) your school. I will make you regret I will make you regret Distance expanded.I regret it. I have no regret about... I work hard every day(改为一般疑问句) _____ ______work hard every day? Don't regret?Don't regret was I I have been studying _____ I can to learn Englishas hard as,so hard as,too hard as,too hard so so答案是哪个?