1. common expressions 常用语

例句：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”。

2. letout 泄露

例句：Speaking of cats, why does letting one out of the bag mean you're revealing a secret? Well, you can thank devious medieval salesmen for this one.
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？

3. the apple of one's eye 对···很重要

例句：And since eyes are pretty precious organs, calling someone "the apple of your eye" meant that they were very important to you. How sweet!
来聊点比较开心的吧，我有告诉过你“你是我眼中的苹果”吗？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，你知道，苹果也和瞳孔一样是圆的。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。多甜蜜啊!

4. brand new 全新的，崭新的

例句：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。