46、 do with 用…..凑合. do without 没有……也行
　　
You can do with your girlfriend.
　　
You can do without your girlfriend
　　
47、 dog tired 特别累、同义：run down. worn out. out of steam
　　
I’m dog tired these days. I’m working on seven articles.
　　
48、 down jacket 羽绒服
　　
49、drive somebody up the wall 让某人发疯；同义：drive somebody out of one’s mind
　　
The sound of all that raffic is driving me out of my mind.
　　
50、 fall back on 依赖
　　
A: Were you able to understand that French novel without any help from theteacher?
　　
B: I did pretty well、 but I had to fall back on my dictionary occasionally.