1、guarantee

例句：Unity is the guarantee of victory.

團結是勝利的保證。

2、insure

例句：To insure the highest volume of milk, the calf is taken away from her immediately after birth.

為了確保生產最大量的牛奶，小牛犢一出生就被立刻從母奶牛身邊帶走。

3、make certain

例句：Make certain you value and allow rest and recovery time.

確信你重視并允許休息和恢復時間。

4、Ensure

例句：But how can you ensure that.

但是如何才能確保這點呢。

5、assure

例句：Jack assured himself that they did as they were told.

杰克確信他們是按照要求的那樣去干的。