It is also pretty clear that for some after the foundation of the polis, there were no city walls.

而且很明显,在城邦建立起来之后的相当长的一段时间内,都没有城墙

耶鲁公开课 - 古希腊历史简介课程节选

I'm going to live here for, who knows how long. Quite a long time.

我打算定居在这儿，不知道多久。会是相当长一段时间。

追忆艾米 - SpeakingMax英语口语达人

Stocks have paid 4% more a year over this incredibly long time period than short-term bonds.

股票在相当长的一段时间里,每年都比短期债券投资收益率,高出4个百分点。

耶鲁公开课 - 金融市场课程节选

It's an anthology of writings or books written and edited over an extensive period of time by people in very different situations responding to very different issues and stimuli, some political, some historical, some philosophical, some religious, some moral.

是书籍文献的选集,由许多人在一段相当长的时间里,在各种各样的环境下,对不同的事件做出回应而写成的，政治的，历史的，哲学的，宗教的，道德上的，无所不有。

耶鲁公开课 - 旧约导论课程节选

Now you keep on trying and because the reinforcement is intermittent you don't expect it as much and so your behavior will persist across often a huge amount of time.

你会不停的尝试,因为此时的强化是间隔强化,你并不会抱有很高的期望,因此，你的行为,通常会持续相当长的一段时间。

耶鲁公开课 - 心理学导论课程节选

He has data for a very long time period, 1802 to 2006, for the U.S.

他的数据是采用美国从1802年到2006年，相当长的一段时间。

耶鲁公开课 - 金融市场课程节选