在很长一段时间里，没人知道火星是什么时候被发现的，谁发现的，也不知道有一种行星可以不用望远镜就能从地球上看到。

It's not known when Mars was found and by whom Mars has been known for a very long time, and one of the planets that can be seen from the Earth without a telescope.

youdao

似乎在很长一段时间里，那一部分被忽视了。

It seemed as if for a long time that part had been neglected.

youdao

但是我们在很长一段时间里一点一点地做到了。

But we did it little by little over quite a long time.

youdao

And archaeologists for a long time were convinced that they would find these destruction layers. But they were disappointed.

考古学家在很长一段时间都相信,他们能找到那些被摧毁的层面，但他们失望了。

耶鲁公开课 - 旧约导论课程节选

I don't know if you know this, but for a long time when movies took place in New York,

我不清楚你是否知道，很长一段时间，电影里发生在纽约的场景，

电影里的中央车站 - SpeakingMax英语口语达人

Once the poleis are in place, they will spend a great deal of time fighting each other.

一旦城邦在某地建立,他们就会花上很长一段时间相互争斗

耶鲁公开课 - 古希腊历史简介课程节选