有关英语的问题请说明原因,最好扩展的讲1.The chair looks very hard ,but it is ve

有关英语的问题
请说明原因,最好扩展的讲
1.The chair looks very hard ,but it is very comforable to __
A.sit B.sit on C.be sat D be sat on
2.My hair is too long.I am going to have it _____
A.cutting B.cut Ccuts D.to cut
3.When he got to the station ,the train ____ for a long time
A.had been away B.had left C,has been away D.has left