题目内容：

because she had never travelled on a train before...travel on是固定结构吗

优质解答

because she had never travelled on a train before...
简单译一下：因为在...她从未乘火车旅行过.
travel on是固定结构吗?
答：不是固定结构!而介词on a train在这里是个词组,意为：“乘火车,在火车上”；
有问题再找我