他们神秘兮兮的眨眨眼。

And they wink.

他们无论对什么都那样神秘兮兮的。

They were so secret about everything.

干嘛神秘兮兮的？你有事情瞒着我吗？

Why so mysterious?Are you hiding something from me?

“无意中看到这个，想必你会对它感兴趣”，信中神秘兮兮的留下了这句话，后面附着一篇文章，摘自一期关于灵长类动物学的美国杂志。

Attached was an article from the American Journal of Primatology.