然而，兰皮诺和其他人对传统主义者的一个基本假设提出了质疑：在整个地球历史中，冰川期是周期性发生的。

Yet Rampino and others question one of the traditionalists' basic assumption: the periodic occurrence of glaciation throughout Earth's history.

youdao

我签订的三年期合同已于上周期满。

I was on a three-year contract that expired last week.

《牛津词典》

这一周期并未被完全转向。

The cycle has not entirely turned.

youdao

Cells can stop in their lifetime at some point in the cell cycle and persist for long periods of time.

细胞生命期可以停止在细胞周期的某个点,并保持很长时间

耶鲁公开课 - 生物医学工程探索课程节选