他们的合同每三年更新一次。

Their contract is renewed every triennium.

三年后，他终于完成了他的研究。

After a triennium, he finally completed his research.

这个项目预计将在三年内完成。

The project is expected to be completed within a triennium.

在过去的三年里，她一直在国外工作。

She has been working abroad for the past triennium.

三年的时间足够让一个人学会一门新语言。

A triennium is enough time for someone to learn a new language.