爆发式增长的英语句子 - 标准学习网

Within just a few weeks, more than half of Harvard's students had signed up.

仅仅几周之内，超过一半的哈佛学生就已注册。

句子分析：使用了过去完成时 had signed up 来表示在过去某个时间点之前已经完成的动作。

英文句子励志句子爆发式增长