on doing用法有个句子 On seeing Mrs.Richards walk towards him,he fled.请问on doing 这个结构是怎么用的?什么情况下用?

on doing用法有个句子 On seeing Mrs.Richards walk towards him,he fled.请问on doing 这个结构是怎么用的?什么情况下用? 有没有work on doing sth这种用法的 share 的全部用法.有share on doing句型吗? decide on doing sth 有这种用法么 go on with sth和go on doing区别如何?有没有go on with doing sth的用法 有spend.on doing sth 请问keep on doing和 keep doing在用法上有什么区别?还有,当表示“继续做某事‘时,keep on doing spend money on doing sth 有这用法吗spend money on doing 与spend time in doing 是这样吗,求详解~ on doing 求英语中反身代词的用法为什么有个句子：Happiness depends on ourselves.为什么ourselves不能换成us? decide 的用法疑问decide on doing sth 和 decide to do 有什么区别么 我说的是 decide on doing sth insist on one’s doing 造个句子 He can nothing change his mind 怎么办翻译 carry on有哪些用法 on的用法有什么 求keep的用法如keep on doing spend on与spend doing的区别和用法? go on的用法不是有个go on with吗? on用法?