let fall
vt. 放下(无意中说出)
例句与用法：
He did not let fall a word about it.
他对这事没漏出一句话来。
I guess what is happening from a few words she let fall.
我从她说的几句话中猜出发生什么事了。
He let fall a suggestion.
他随便提出了一项建议。
From something he let fall, I believe they are planning to redesign the machine.
从他透露的话里看，我想他们是打算重新设计这台机器。