I don't know how to answer it.

因为我不知道该如何回答。

youdao

I really don't know how to answer that!

我真的不知道该如何回答这个问题！

youdao

I don't know how to answer the question.

我不知道如何回答这个问题。

youdao

I think the truth of the matter has to be-- I think the answer right now is, we don't know how to give that story.

我认为,事实上,目前的答案就是,我们还没法做出那种解释

耶鲁公开课 - 死亡课程节选

So, while - to borrow some words of wisdom from WPP's Martin Sorrell - "we don't know the answer" to how exactly the small screen revolution will change advertising, mobile probably won't radically alter the size of the industry.

CNN: Will mobile kill digital advertising?