四、过去完成时 had done → had been done 常搭配的时间状语:by then, until then,by that time, before 2000, by the end of last month, by the time he was ten,… 过去完成时的用法: 1.过去的过去;到过去某个时间为止的动作 2.hardly/scarely(过完)… when(一般...