Question: What are the best ways to translate `For all you know`?

For example:

> 
> For all you know, she could be lying to you.
> 
> 
> In response to a friend getting upset that her friend isn't picking up her phone, I respond, "For all you know, something could have happened."
> 
> 
> A neighbor sends us some vegetables and I tell my wife, "We better wash them first, for all we know, they could be covered in pesticide"
> 
> 
>

Answer: 
天知道 is also ok

"For all you know, something could have happened."
說不定發生了一些事情

"We better wash them first, for all we know, they could be covered in pesticide"
還是先洗洗，天知道有沒有農藥
For all you know, she could be lying to you.

听你所见,她可有在骗你.