All these changes happened over a period of time.

所有这些变化都是在一段时间内发生的。

She spent a period of time working with people dying of cancer.

她用一段时间帮助即将死于癌症的人们。

The reducing candy content in the dextrinization of the dextrin increased and decreased after a period of time.

糊精在反应过程中的还原糖含量呈现先升高后降低的趋势。

Total cost in a period of time

某一时间段内的总成本

So this will play out over a period of time.

所以这要经过一段时间才会出现结果。