状语从句This is the ship where we travelled during the holidays.
状语从句This is the ship where we travelled during the holidays. 等价于this is the ship on which we travelled during the holidays 为什么是ON WHICH,不是BY WHICH什么的.如何确定使用什么介词? 我记得初中时老师经常说by bus,by ship,这里为什么就不能用了,