(By the time) she got to class,the teacher has already started te_英语解答

(By the time) she got to class,the teacher has already started teaching Awhen Bbefore
为什么不能用before?
对不起
应该是 had already started..

人气：126 ℃　时间：2019-08-18 17:00:37

解答

原来用的By the time是指一个时间点,所以应当用when.before 是一个时间段了.