DONT EXPLAIN, JUST TRUE OR FALSE. Thanks

11.Externalities may be present in perfectly competitive markets.

a.True

b.False

12.There are four distinct market structures, according to neoclassical economists.

a.True

b.False

13.If there are changes in consumer tastes, a perfectly competitive market will not be affected.

a.True

b.False

14.If price is below the long-run average cost, firms will enter the market in the long run.

a.True

b.False

15.The increase of cost that is required to increase output of some good or service by one unit is marginal cost.

a.True

b.False

16.The difference between total revenue and total costs is pure economic profit.

a.True

b.False

17.One condition for a perfectly competitive firm to be in long-run equilibrium is that it has no incentive to produce more or less output.

a.True

b.False

18.If there are no legal barriers to market entry, it is called free market entry.

a.True

b.False