fail后可接to do sth吗,不是接fail in doing sth?为什么?

fail后可接to do sth吗,不是接fail in doing sth?为什么? fail to do sth和fail in doing sth的区别 fail in sth..fail to do sth.啥意思? fail的几种用法fail in sthfail in doing sthfail to do sthfail sth fail to do sth=? fail to do与fail (in) sth有什么区别啊 fail to do sth解释下. fail in doing sth中的in能不能省略 fail sth.和fail in sth.有什么区别? fail to do sth与forget to do的区别 fail to do sth的同义词组是什么? forget to do sth和fail to do sth 的区别