我不知道多少学校已经倒塌。

I don't know how many schools collapsed.

youdao

我不知道多少城镇被破坏。

I don't know how many towns were destroyed.

youdao

我有点出汗，不是因为紧张——我回答类似问题已经不知道多少遍了——而是因为这里的暖气实在太足了。

I perspire a little, not because I am nervous - I have been through this thing God knows how many times - but because the central heating here is very good.

youdao

Obviously we don't expect you to know exactly what the distances are, but you should be able to compare them relatively.

当然我们不要求你么,要能知道具体这些位置是多少，但你们要能够相对比较它们。

麻省理工公开课 - 化学原理课程节选

Yeah, it was a good film. I mean, I don't know how much of it was accurate or not.

它是一部好电影。我的意思是，我不知道有多少内容是准确的。

英国电影的魅力 - SpeakingMax英语口语达人

I don't know how many kids, generation after generation, get in trouble because they do not remember the following fact.

我不知道有多少孩子,一代又一代,因为没有记住下面的内容而遇到困难

耶鲁公开课 - 基础物理课程节选