总统任期四年。

The president occupies the position for four years.

《牛津词典》

总统的任期不得超过两届，每届四年。

The presidential mandate is limited to two terms of four years each.

《牛津词典》

讲师这一职务任期三年。

The lectureship is tenable for a period of three years.

《牛津词典》

From 2006 to the day he left the office on Tuesday, January 20, 2009.

任期从2006年,到2009年1月20号。

普林斯顿公开课 - 国际座谈会课程节选

And we did a presentation on his foreign policy over his 12 year presidency.

我们展示了一下他在12年的总统任期之间的外交政策。

要做好角色分担 - SpeakingMax英语口语达人