1. Expression：with a wet finger

Explanation：with ease. （毫不费力地，轻松地）

Example：Go ahead, you will finish the work with a wet finger.

动手干吧，你将会轻而易举地完成这项工作。

How did the escaping prisoners get past the guards with a wet finger?

那些越狱的囚犯是怎样毫不费力地躲过警卫的？

He brought off his speech with a wet finger.

他毫不费力地使自己的演说获得了成功。

2. Expression：shake one’s finger at someone

Explanation：To blame or warn someone. （责备或警告某人）

Example：Her boss shaked his hand at her for being late for work.

由于上班迟到,她老板狠狠地责备了她。

Harry’s mother shakes her hand at him for cutting in on what Susan was doing.

Harry的母亲因为Harry干涉苏珊所做的事而责备他。

I cannot find it in myself to shake my hand at a mother who steals for a hungry child.

我不忍心责备为饥儿行窃的女人。

The teacher shaked her hand at him but his classmates stood up for him.

老师责备他，但同学们支持他。

3. Expression：look through one’s finger at someone

Explanation：To pretend not to see someone. （装作没看见……）

Example：I saw the little boy slip into the kitchen and snatch a bun but I looked through my fingers at it.

我看见这小男孩溜进厨房，拿了一个小圆面包，可是我假装没看见。

I didn't know that to humour her and I should look through my finger at Mr. Heathcliff.

我不知道为了迁就她，我应该假装没看见Heathcliff先生。

He turned aside, looking through my finger at me.

他转过脸去，假装没看见我。