intwoyears是什么时态

　　例句：

　　He trebled his earnings in two years.

　　他在两年间收入增加了两倍。

　　She completed her degree in two years.

　　她在两年内修完了学位。

　　It was his fourth pink slip in two years.

　　这是他在两年内收到的第四份解雇通知书。