21、 back up
　　
1) 累积
　　
The subwayis 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.