－Miss Jones once _________ music at a local college for ten years and now is an actress.

－No wonder I often hear her sing some pop songs.

A．had taught

B．has been teaching

C．taught

D．is teaching

死亡原因不明的死畜肉，应如何处理（）

A.冷冻后食用

B.高温加热食用

C.盐腌后食用

D.辐照后食用

E.一律不准食用