11. Butter [someone] up
To butter someone up is to please or flatter someone in order to win his or her favor. This separable phrase may be used in the format butter [someone] up or butter up [someone].
Butter someone up意为取悦或奉承某人以赢得他/她的欢心。这个可分短语可以以两种形式出现即butter [someone] up或者butter up [someone]。
Everyone seems to be trying to butter up the new boss hoping to become her favorite.
12. Food for thought
Food for thought refers to something that’s worth thinking carefully about.
Food for thought指值得仔细思考的事情。
Moving to another state is food for thought for many of those affected by the recent hurricanes in Texas and Florida.
13. A smart cookie
Here’s an easy one. A smart cookie is an intelligent person.
这个习语很简单，a smart cookie指聪明的人。
It shouldn’t be hard too hard for a smart cookie like you to learn Spanish.
14. Packed like sardines
What do you see when you open up a can of sardines? Yes, the fish crammed inside the can. So packed like sardines describes a place or situation that’s very crowded with people (or animals).
打开一罐沙丁鱼罐头的时候，你看到的是什么？是的，里面塞满了鱼。所以packed like sardines用来形容非常拥挤的地方。
Were you at the football game last night? The stadium was packed like sardines.
15. Spill the beans
You accidentally knock over a bowl of beans and they all spill out. Think of this image and you’ll remember that spill the beans means to accidentally or prematurely give out information that’s supposed to be kept secret.
你不小心撞翻了一碗豆子，它们都被洒出来了。想想这幅画面，你就会明白spill the beans意为泄露了本该保密的消息。
We were planning a surprise birthday party for Joyce this weekend. But this morning, Owen spilled the beans and now it’s no longer a surprise.
16. A bad apple
Imagine a basket of apples with one rotten apple inside. This picture will help you remember that a bad apple is someone who creates problems or trouble, or is a bad influence on the other people in a group.
想象一幅画面，一篮子苹果里面有一个坏苹果。这幅画面会帮助你理解a bad apple是指制造问题惹麻烦的人，或者是对小组内其他人产生不好影响的人。
Instead of focusing on college, he spends his time hanging out with bad apples.
17. Bread and butter
Bread and butter is a basic food that many of us eat. So the idiom bread and butter refers to a job that makes the money you need to live and afford basic necessities like food, housing, etc.
面包和黄油是一种基本食物。因此习语bread and butter就是指一份可以赚钱的工作，可以用来提供基本的生活资料，比如食物，房子等。
Fishing is the bread and butter of the friendly people who I met on the island last summer.
18. Buy a lemon
To buy a lemon means to buy something (usually a motor vehicle) that doesn’t work well and is therefore worthless.
Buy a lemon以为买没有用处的东西，因此毫无价值。
The car looked so new and shiny I had no way of knowing I was buying a lemon.
19. A hard nut to crack
Is it easy to crack open a nut? Not always. Well, a hard nut to crack refers to a person who’s difficult to deal with or to get to know.
把坚果打开容易吗？不是很容易吧。A hard nut to crack是指难对付或者难了解的人。
I tried to be friendly with her but I was told she’s a hard nut to crack.
20. Have a sweet tooth
Do you like eating cakes, candy and other sweet-tasting food? If you do, then you can say you have a sweet tooth.
你喜欢吃蛋糕，糖果和其他甜甜的食物吗？如果你喜欢你就可以用have a sweet tooth来形容自己。
Yes, I definitely have a sweet tooth. I can never walk past a bakery and not stop to buy myself a slice of chocolate cake.