—What’s the matter with you ?                   

—Oh, I’m not feeling well in the stomach . I         so much fried fish just now .

A．shouldn’t eat

B．mustn’t have eaten

C．shouldn’t have eaten

D．mustn’t eat

（）由永久磁铁、磁钢、音圈、音膜、输出变压器等组成。

A.动圈式传声器

B.普通电容式传声器

C.压电陶瓷蜂鸣器

D.舌簧式扬声器