train leaves at 6pmthe train leaves at 6pm.So I have to be at the station ( )5.40pm at the lastest.A.by B.before选A.是最迟到.为止的意思?那before为嘛不对
问题描述：
train leaves at 6pm
the train leaves at 6pm.So I have to be at the station ( )5.40pm at the lastest.
A.by B.before
选A.是最迟到.为止的意思?那before为嘛不对
答
by 比before具体 几乎等于at
before比较 模糊 不超过 5.40 的任何 时间 都可以是before 比如 1 点
答
楼上的回答不错.
the train leaves at 6pm.So I have to be at the station before 5.40pm.
the train leaves at 6pm.So I have to be at the station by 5.40pm at the lastest.
你可以体会下二者的差别.