例句：

　　He trebled his earnings in two years.

　　他在兩年間收入增加了兩倍。

　　She completed her degree in two years.

　　她在兩年內(nèi)修完了學(xué)位。

　　It was his fourth pink slip in two years.

　　這是他在兩年內(nèi)收到的第四份解雇通知書(shū)。