A: I have no idea about what to do.
我不知道下一步怎么辦。
B: Maybe you can pick Mary’s brains now. She knows a lot about stocks.
也許你可以挖挖瑪麗腦筋里的東西，她對股票很在行。
A: Let me have a try.
我去試試吧。
地道表達：
pick someone’s brains
解詞釋義：
to ask for information or advice from someone who knows more about a subject than you do，翻譯為“剽竊或竊取別人的智力成果 ”。
支持范例：
I'd love to pick your brains about computers - you seem to be the expert around here.
我要玩玩你腦袋里電腦的知識，你在這兒似乎是電腦專家呀。
Do you mind if I pick your brains on a minor legal matter?
我想向你討教一個小小的法律問題，行嗎？
He refused to prepare for the exam,but counted on being able to pick his roommate's brains.
他不肯準備考試,仗著他能夠向室友請教。
I've come to pick your brains.
我是來討教你的專門知識的。
詞海拾貝：
1. know a lot about：對......知之甚多
范例：You seem to know a lot about him.
你好像很了解他。
It means you know a lot about movies and you have seen quite a large number of them.
你很懂電影并且看過很多片子。
I don’t know a lot about China yet, but Im eager to learn.
我對中國還不太了解，但我很想知道。
It seems you know quite a lot about it. I'd better ask for your advice when I have the chance.
看來你知道的真不少，有機會得好好向你請教。
2. have a try：試一試
范例：If you can' t open the box, can I have a try ?
如果你打不開這個箱子，我能試一試嗎？
I will have a try even though I should fail.
哪怕失敗，我也要試一下。
Don't slight a penny. Have a try to know how it is earned.
不要小看一分錢。不妨自己去掙掙看。
Why not have a try? Maybe you will lose a good chance.
為什么不試試？沒準兒你放跑了一個大好機會。
3. have no idea：不知道
范例：We have no idea how to persuade him to give up the idea.
我們不知道如何說服他放棄這個念頭。
That' s a difficult question ; I have no idea of the answer.
這是一個難題，我想不出答案。
If you have no idea about it, consult a dictionary, please.
要是你對這個問題不清楚, 請你查字典得了。
I have no idea why he resigned his post.
我不知道他為何辭去他的職務。