21, back up

　　1) 累积

　　The subway is running behind schedule, and traffic is backed up for blocks. I don’t know if we’ll make the 6:30 show.

　　2) 支持

　　I’ll back it up.

　　22, be bound for 到……地方

　　The bus is bound for New England.

　　23, be (feel) myself 找到自我

　　I’m feeling myself again.

　　24, be burned up 生气

　　She was really burned up at the news.

　　25, be hard up for

　　I’m hard up for clothes, but I have a lot of books.

　　26, fill a prescription 按处方抓药

　　Would you please fill this prescription for me?

　　27, fill in for 代替; 同义：fill one’s place(position, shoes); take the place of; take over Say, Dave, can you fill in for me tonight at the restaurant? I’d like to go out of town.

　　28,food for thought 令人思考的东西;同义：thought-provoking

　　There is a lot food for thought in what he had to say.

　　29,for nothing 免费

　　To pay to see that movie would be foolish, when you can see it on TV for nothing.

　　30,from top to bottom 从上到下

　　A: Maybe you lost your wallet in this room.

　　B: I’ve searched it from top to bottom..