—How often do I need to feed the birds?

—They _______ food every day, or they will be hungry.[ ]

A. must give

B. mustn't give

C. must be given

D. mustn't be given

在组织设计中，属于错误做法的是下列哪项（）

A.实行首脑负责制

B.副职服从正职

C.一级管多级

D.实行参谋制