Welcome to English in a Minute.
If you have heard American English or watched an American TV show, you probably have heard this:" Hear a pin drop."
如果你听过美式英语或者看过美国电视，你可能听到过“Hear a pin drop（异常安静）”
What does this phrase mean?
Let's see whether we can find out by listening to an American English conversation.
I can't believe he said that. And then the room was so quite. Nobody said a word.
Yeah, I mean it was so quiet you could hear a pin drop.
Pins are small and don't make noise when they fall to the floor.
So when you say you can "hear a pin drop," it means that the room is silent.
Usually, that's because the people are surprised or excited about something.
And that's English in a Minute.