1.He left two hours ago.He___home. A.must arrived B.must have arrived C.can arrived D.can have arrived2.I'm very busy. I have a lot of work___.A.do B.to do C.doing D.to doing3.I think we'll go there___train. A.by B.on C.take D.with4.Why does he not come today? He___be ill. A.by B.on C.take D.with5.Jim was a good student when he was___.A.in school B.in the school C.at school D.at the school