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。

《牛津词典》

Add up all the income you've received over the period in question.

把相关时期内你获得的所有收入加起来。

《柯林斯英汉双解大词典》

A lot of those cave drawings you have all seen come from this period.

你们看到的很多洞穴壁画都来自这个时期。

youdao

Their advice may be all the more helpful during this period of economic recession.

VOA: special.2009.09.11

And there was the confluence of religion and business and science and all of these things that changed dramatically at about that period of time.

当时宗教，商业,科学等等都有了交叉点,它们在那个时期发生了巨大的转变。

普林斯顿公开课 - 人性课程节选

So if we're talking about the third period, that starts with sodium and it goes all the way up to argon.

所以如果我们谈论第3个周期，它从钠开始,一直到氩。

麻省理工公开课 - 化学原理课程节选

Bernanke was unable to avoid expressing his concerns about the US debt ceiling at his free-for-all question period yesterday.

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The goal was the first that Anderson has given up after the first period all season.

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If sales of the combo are material at all during that period, Ranbaxy and Pfizer could wind up splitting them for years.

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