1. To hold water 站得住脚，说得通

　　按字面解释，To hold water当然可以说是“不让水漏出来”。但是，它还可以引申为指某人的论点、借口、理由站得住脚。美国人经常说："That excuse simply doesn't hold water." 意思是：那个借口根本站不住脚。

　　Several of his suggestions about changes in the government simply don't hold water.

　　他有关政府改革的意见中有几条根本说不通。

　　2. Like water off a duck's back 毫无意义

　　鸭子身上的毛就像雨衣一样，水在上面呆不住，一下全滑掉了。因此，like water off a duck's back指的就是某件事毫无意义，不起作用。

　　The doctors tell us it’s dangerous to smoke, but such good advice rolls off some people like water off a duck's back.

　　医生都告诉我们抽烟对身体是有害的。可是，这种合理的建议对于有些人来说就像耳边风一样，毫无作用。”

　　3. To make someone’s mouth water 让某人流口水

　　让某人嘴里流水自然就是让某人流口水的意思了。

　　The roast ducks that restaurant serves is my favorite dish. Every time I think about it, it makes my mouth water.

　　我最喜欢吃那个饭馆的烤鸭。每当我想起它我就会流口水。