NO.PZ2023010401000030
问题如下：
Under conditions of perfect competition, in the long run firms will most likely earn:选项：
A.normal profits. B.positive economic profits. C.negative economic profits.解释：
Competition should drive prices down to long-run marginal cost, resulting in only normal profits being earned.
中文解析：
竞争应该将价格压低至长期边际成本，从而只赚取正常利润。
为什么不选b？
