01.know one's onions 精明强干
Don't worry about Jack,he knows his onions.
02.the apple of one's eye 某人的挚爱
I am the apple of my father's eye.
03.sour grapes 吃不着葡萄说葡萄酸
Leave him alone,it is just sour grapes.
04.go nuts 失去理智
Are u go nuts?
05.go bananas 变得激动、疯狂
Don't talk about math any more.I'll go bananas.
06.have other fish to fry 另有打算
I will not push u to do this work because we have other fish to fry.