11, allergic to 对|……过敏
Oh man! Something in this room is making my eyes itch. I must be allergic to something.
12, at sb’s service 愿为某人服务
I am at your service at any time.
13, around the clock 24小时不停
Martha studied around the clock for management exam.
14, as far as I know 就我所知
15，at home with 对…..很熟悉
She is at home with problems like this.
16, back out
1) 退出
A: Wasn’t Bert supposed to sing tonight?
B: Yes, but he backed out at last minute
2)不履行
She finally backed out of her promise.
