– useful information you gave us! Thanks a lot! – You are welcome.A. HowB. WhatC. What an

问题补充：

– useful information you gave us! Thanks a lot!

– You are welcome.

A. How

B. What

C. What an

D. What a

答案：

A. How

(答案→)B. What

C. What an

D. What a

解析：what引导的感叹句其结构为what +adj+n{u}+主谓！因为information为不可数名词，故选B