bomb 炸弹，shell 壳，bombshell 却是……

　　drop a bombshell

　　宣布令人震惊的消息

　　bomb 是“炸弹”，shell 是“壳”，那 bombshell 是不是“弹壳”呢?

　　其实不然，bombshell 释义为：an event or a piece of news which is unexpected and usually unpleasant 出乎意料的事情，意外消息(常指不幸的消息)

　　eg. His resignation after thirteen years is a political bombshell.

　　短语 drop a bombshell 并不是“投下一个弹壳”，而是“宣布一个重磅消息(常指不好的消息)”

　　eg. My sister dropped a bombshell by announcing she was leaving her job.

　　我姐姐宣布她要辞职，这让大家大吃一惊。

　　bomb 相关用法补充

　　be the bomb 非常好，很轰动

　　That new restaurant is the bomb!

　　那家新餐馆好极了。

　　cost a bomb 花费很多钱;值很多钱

　　I'd love to buy a Porsche, but they cost a bomb.

　　我倒是想买辆保时捷，可实在太贵了。

　　make a bomb 挣大钱

　　I could make a bomb selling these cupcakes!

　　卖这些杯蛋糕，我可以赚一大笔钱!