a bombshell直译过来就是：“一个炸弹，一个突发事件”，这个短语的正确意思是：“令人震惊的人或事或消息”。因此，当美国人说"Whoa, that is a bombshell."时，他/她要表达的意思就是:"That news is really amazing."、"That's a really breaking news."。
Shirley: Honey, I hear that our manager is going to be promoted and transferred to the headquarters in New York.
Benjamin: Really? Whoa, that is a boom shell. Guess who will be the new manager?
①All workers of our company are going on strike for better pay.
②He had a big quarrel with his colleague for promotion.
③Our manager has resigned and I will take his place.
④Today is a red-letter day for me. I got a promotion.
bombshell n. 突发事件，令人震惊的事
His resignation after thirteen years is a political bombshell...
The police told me. It was a bombshell. I had no idea.
He dropped the bombshell. He told me he was dying.