fail和fail in 有什么区别?

fail和fail in 有什么区别? fail sth.和fail in sth.有什么区别? fail和fail in用法 fail 和fail in的用法区别和意思 fail to do与fail (in) sth有什么区别啊 fail to do和 fail doing有区别没? fail to do sth和fail in doing sth的区别 fail in the exam fail the exam区别 Fail fail a test 和fail the test的区别 Fail in plan, is planning to fail什么意思? fail,failure的区别