垄断竞争企业广告费的最优化条件是：广告费的边际收入=广告费的边际成本。
参考答案：对
— Is the watch on the bed?
— _____.
[ ]
A. Yes, it isn't
B. No, it is
C. Yes, it's
D. No, it isn't
过热蒸汽是不饱和的（）
