a表示一个一位数，b表示一个两位数，把a放到b的左边组成一个三位数，则这个三位数可以表示为（　　）

A．ab

B．10a+b

C．100a+b

D．a+b

Speaker A: Nancy, you look very well.

Speaker B: Thank you, Jane. You look wonderful too. Your weekend swimming must have done good to you.

Speaker A: ().

A. You think so That’s encouraging.

B. That’s very kind of you.

C. Are you serious Thank you anyway.

D. Are you kidding I don’t believe it.