like looking for a needle in a haystack:大海捞针

Searching for one man in this city is like looking for a needle in a haystack.
在这个城市里找一个人无异于大海捞针.

Beat around the bush:拐弯抹角地讲话;绕圈子
原意是指猎人在打猎时,先在草从附近拍打,以让鸟类猎物受惊而现出足迹,从而引申出借由迁回的方式,不针对问题回答,即拐弯抹角.
Stop beating around the bush and tell me what you want.
别绕来绕去了,告诉我你想要什么吧.