— What do your parents do?

— They ______ doctors. [ ]

A. are all

B. are both

C. all are

D. both are

中药虫蛀的防护措施一般有（）

A.清洁卫生

B.密封包装

C.控制环境因素

D.对抗贮藏

E.高温杀虫