Today we're back with another common expressions video because you all thought the last one was the bee's knees. 今天我们又带来另一部有关常用语的影片，因为你们都觉得上一部是“蜜蜂的膝盖”。

But what the heck does that even mean? And also, do bees have knees? Well, yes. Yes, they do. 但那到底是啥意思啊？还有，蜜蜂有膝盖吗？嗯，有的。没错，它们有膝盖。

And the pollen that they carry on their legs might be why "the bee's knees" is slang for "excellence." 而它们脚上携带的花粉可能就是为什么“蜜蜂的膝盖”是用来表示“优秀”的俚语。

However, that wasn't always the case. 然而，并不总是那样的。

It used to be a nonsense phrase that people would try to trick their friends into saying when asking for items in the store. 这以往是人们捉弄朋友讲出口的蠢话，要他们在店里买东西时这样说。

But in the 1920s, flappers repurposed the term along with other animalistic phrases, like, "the cat's whiskers." 但在 1920 年代，时髦女子们将其他和动物有关的话和这个用法重新应用，像“猫咪的胡须(意思是了不起)”。

Speaking of cats, why does letting one out of the bag mean you're revealing a secret? 讲到猫，为什么让一只猫从袋子里跑出来就代表你泄露了秘密呢？

Well, you can thank devious medieval salesmen for this one. 嗯，你可以感谢中世纪的奸商们带来这个用法。

If you were alive in the Middle Ages and wanted to buy a pig at a market, that pig would be put in a bag and given to you to take home. 如果你活在中世纪然后想在市集买一只猪，那只猪会被放在袋子里让你带回家。

But don't be too trusting. Some salesmen may give you a cat in a bag instead. 但可别太轻易相信别人。有些商人可能改成放了一只猫在袋子里给你。

And while you're at it, break a leg! Before a big performance, you're probably incredibly nervous, 在你讨论这些常用语时，“摔断一条腿吧”!一场盛大演出前，你可能超级无敌紧张，

but if someone wished you good luck, it's thought that evil spirits would make you do poorly. 但如果有人祝你好运，人们认为恶灵就会让你表现不佳。

So people said "break a leg" instead to discourage the evil away. 所以人们代而说“摔断一条脚”来把坏东西赶走。

Those theater people sure are spooky—talented but spooky. 那些剧场的人们真是很恐怖－－有才华但令人毛骨悚然。

On a lighter note, have I ever told you that you are the apple of my eye? 来聊点比较开心的吧，我有告诉过你“你是我眼中的苹果”吗？

Back in the day, we thought that the pupil of someone's eye was a solid object and called it an apple because, 在过去，我们认为人的瞳孔是个结实的物体，并称瞳孔为苹果，因为，

you know, apples are also round like a pupil. 你知道，苹果也和瞳孔一样是圆的。

And since eyes are pretty precious organs, calling someone "the apple of your eye" meant that they were very important to you. 而因为眼睛是蛮珍贵的器官，称某人“你眼中的苹果”就代表他们对你来说非常重要。

How sweet! 多甜蜜啊!

So what are some other common expressions that you want us to explain? 还有其它哪些你想要我们解释的常用语呢？

We're glad you are liking these because we do too. 我们很高兴你们喜欢这些影片，因为我们也很喜欢。

Make sure you come back every Monday for a brand new video. 每周一务必回来收看全新影片。

And if you want even more Life Noggin, check out this video we did on what happens when we starve. 如果你想看更多 Life Noggin，看看我们录的这部关于肚子饿时会发生什么事的影片。

And follow us on Facebook and Twitter. As always, I'm Blocko. This has been Life Noggin. 在 Facebook 和 Twitter 上追踪我们。然后老样子，我是 Blocko。这是 Life Noggin 频道。

Don't forget to keep on thinking. 别忘了要不断思考喔。