边际收益等于边际成本时,企业的正常利润达到最大化。
参考答案:错
The famous actress became________,and couldn't say a word when asked about her father,who
passed away only last month.[ ]
A.choked
B.frightened
C.swelled
D.squeezed
多方面呈现各种直观材料或事例的形式,以便突出事物本质特征的方法是【】
A.变式
B.定势
C.具体化
D.系统化