We seem to also have a different account of how long the flood lasted; there are more subtle contradictions throughout as well.

关于洪水持续了多久，我们有不同版本;,他们之中有很微妙的不同。

耶鲁公开课 - 旧约导论课程节选

I need to know how long, so that I can let my roommates know.

我得知道大概有多久，这样我就可以告诉我的室友们了。

How long实战 - SpeakingMax英语口语达人

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

How long have you been suffering from this nightmare?

你受这种折磨有多久了？

How long课堂 - SpeakingMax英语口语达人