A firm in a perfectly competitive industry that seeks to maximize profit is most likely to continue production in the short run as long as which of the following conditions exists Price is equal to or greater than :（）

A. average fixed cost.

B. average total cost.

C. average variable costs.

诊断急性呼吸窘迫综合征的必要条件是()
反映机体是否缺氧的重要指标是()
反映肺泡毛细血管膜弥散能力的有用指标是()

A．血氧饱和度

B．动脉血氧分压

C．氧含量

D．氧合指数

E．肺泡-动脉氧分压差