疲惫或瓜代负荷是一个负载，其范围和签订的变动时间。

A fatigue or alternating load is a load whose magnitude and sign are changed which time.

youdao

我们对这些变动抗议了很长时间，但最终不得不屈服。

We protested about the changes for a long time, but in the end we had to submit.

youdao

时间安排也许会有些小小的变动。

There may be some minor changes to the schedule.

《牛津词典》

You could take weights on people measured over a period of many years and look at the variability over time in weight and then link it to things like heart disease and cancer, and I'll come back later and talk about the results of that particular study.

我们还可以得到人们很长一段时间里,每年的体重数据,观察体重随着时间变化的变动,并将观察结果与心脏疾病和癌症联系起来,我等一下会告诉大家这项研究的结果

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选