【单选题】If a perfectly competitive industryis in long- run equilibrium, all frms
A.
have equal marginal costs.
B.
) have identical supply curves.
C.
operate at the point where marginal cost is greater than averagetotal costs.
D.
have identical plant sizes.
【单选题】If a firm buys its labor in a competitive market, then a short-run increase in the price of the firm's output will cause the firm to
【判断题】2012年1月,Z-Corp公司被美国3Dsystems公司收购。
【单选题】If a perfectly competitive market is in long-run equilibrium and there is a permanent decrease in demand, then
A.
some firms will incur economic losses.
B.
firms are no longer maximizing profits.
C.
some firms must immediately exit.
D.
each firm must produce less output in the new long run equilibrium and earn less economic profit.