useful invention(发明) the computer is!A. What anB. What aC. HowD. How a

问题补充：

useful invention(发明) the computer is!

A. What an

B. What a

C. How

D. How a

答案：

A. What an

(答案→)B. What a

C. How

D. How a

解析：此题考查是感叹句。中心词是名词所以用what来引导useful的第一个音素是辅音音素故其前加a.