of
be sure of sth.肯定mybrotherfailed( )geting hislicenceinfail in sth.做某事失败smoking ismuchhad () your body你能不能不要就多个问题发一个个追问啊？one by one OK?Smoking is much bad for your body. 下不为例追问是让你就这个题目我没讲清楚的地方继续问，别跑出去跑太远