伯希村的石头围墙使用当地采掘的石灰岩建成的。没人能说清楚它们矗立在这里有多久了，也不知道何时开始兴建。

The Bories are rock enclosures fashioned from field-clearing limestone, and no one is quite certain how long they have been standing here or when they were first built.

youdao

40岁的约翰·贝克已经不记得他已经多久露宿在外甚至从什么时候开始的都不知道，他说也许有一天他会向埃斯格拉寻求帮助。

John Banks, who is 40 and cannot remember how long he has lived unsheltered, or how it happened, said he might ask for Esguerra one day.

youdao

有几次在我们不知道他能坚持多久时我们很有节制的让他上场，他却总能打满90分钟。

But we have played him on the limit a few times where we didn't know before the game how long he would last. He always manages to get through the 90 minutes.

youdao

One that seems to be in fashion these days, although you never know how long the fashion lasts, is: internal uprisings that somehow these monarchical areas, when life got tough, the people must have risen up against them.

有一个理论现在很流行,虽然不知道流行了多久,那就是认为,这些王国中起义的内部原因是,当民生困苦时,人们就必然奋起反抗

耶鲁公开课 - 古希腊历史简介课程节选