NO.PZ2023010401000031
问题如下：
A firm that increases its quantity produced without any change in per-unit cost is experiencing:选项：
A.economies of scale. B.diseconomies of scale. C.constant returns to scale.解释：
Output increases in the same proportion as input increases occur at constant returns to scale.
中文解析：
产出的增加与投入的增加成同样的比例，以恒定的规模回报发生。
规模经济不就是说每增加一个产量成本不变？
