by __ train 是用a 还是the 还是/

by __ train 是用a 还是the 还是/ 乘火车的费用是乘飞机费用的一半用英语怎么说?The fare by train is __ __ the __ by plane. 英语中by bike=on a bike还是in a bike by train =on a train还是in a train? 是by the train 还是take the train?还有,是by the plane还是take the plane? We go to Beijing on a train.请问是on a train还是in a train? It's to travel by plane than by train.(quick)到底是用形容词还是用副词呢? this is the train _____定语从句this is the train (on which) we will go to Beijing.为什么不可以用by which?不是可以表方式吗?先行词是train还是the train?有什么区别? 谁会这道题：This is the train __ This is the train ____ we went to Shanghai. [ ] A.on which B.by that C.by which D.on that She ____without a coach.请问填什么?我不知道train 的用法 :1.train是及物动词还是不及物动词.2.train什么时候用主动语态还是被动语态 i perfer to travel by train .traveling by train is cheaper than traveling by air.i perfer to travel by train ___ traveling by train __ __ __ traveling by air. I __ (肯定) he is going there by train 1.we are planning to go to paris by train[用take a train的改] 乘火车旅行很有趣.It is __ __ __ by train It's only a short trip ( ) a train.括号里填by 还是 on?说明理由 All flights __ because of the terrible weather,they had to go there by train.A having been canceledB had beed cancledC having canceledD were canceled正确答案是A 2和4为啥不行 take a train和by train的区别是什么 by train 和on a train 是什么短语 到底是 we go there on a train 还是 on the train?