41.cost somebody an arm and a leg

　　A: Did you see the diamond ring Bill gave to Linda?

　　B: I sure did. It must have cost him an arm and a leg.

　　42. cut it out 闭嘴

　　I told you to cut it out.

　　43.be cut out for 生来时做……的

　　Dr. Hamilton doesn’t feel Larry is cut out for the medical profession.

　　44.department chair 系主任

　　I didn’t write that memo to the department chair.

　　45.dirt cheap 非常便宜

　　A: You’ve already furnished your apartment?

　　B: I’ve found some used furniture that was dirt cheap.

　　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 the teacher?

　　B: I did pretty well. but I had to fall back on my dictionary occasionally.