It was a period of intense activity.

那是活动激烈的时期。

《牛津词典》

It was a period of rest and recuperation.

那是一段休养的时间。

《牛津词典》

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》

The Harlem Renaissance was a period in which black artists explored their culture and showed pride in their race.

VOA: special.2009.02.22

I see this as a course that's an introduction to the literature of a period, to modern poetry.

我觉得，这只是一门引导性课程,引导大家关注某一时期的文学创作和现代诗歌。

耶鲁公开课 - 现代诗歌课程节选

And it turns out that simply by counting the number of those spikes that occurs at a period of time.

随后，只要数一数在一定时间内,产生的尖峰脉冲的数量。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

If anything, we are in the middle of a period of increasingly good behaviour.

BBC: Is the teen rebel a dying breed?

There was a period of time when there wasn't much emphasis put on antibiotics.

NPR: Tracking a New Strain of Drug-Resistant Staph

But traders also suggested a correction was expected, following a period of rising markets.

BBC: Business