You have hit the nail on the head.
你说到点子上了。
拉丁谚语
You have hit the nail on the head.
你说到点子上了。
You have hit the point exactly.
你说到点子上了。
You have left the sheep with the wolf for safe custody.
你把羊留给狼安全看管。
You have spoilt the wine by adding water to it.
你往酒里加了水，把酒给糟蹋了。
You have to separate the chaff from the wheat.
你必须把谷壳和小麦分开。
You hold an eel by the tail. [You are dealing with a slippery fellow.]
你抓着鳗鱼的尾巴。(你在和一个滑头的家伙打交道。)
You keep making that face and it'll stay that way.
你继续做那个表情，它就会一直这样。
You know not what the evening may bring with it.
你不知道这个夜晚会带来什么。
You let the cat out of the bag.
你泄露了秘密。
You make an elephant of a mouse.
你把老鼠变成大象。
You may as well talk to the sea-shore.
你还不如跟海滨谈谈。
You may judge a man by his countenance.
你可以从一个人的相貌来判断他。
You may know a lion by his claw.
凭爪识狮。
You must howl with wolves if you wish to be one of their herd.
如果你想成为狼群中的一员，你就必须和狼一起嚎叫。
You must rave with the insane, unless you would be left alone.
你一定是疯了，除非你想一个人呆着。