Suppose that a perfectly competitive firm faces a market price of $7 per unit, and at this price the upward-sloping portion of the firm's marginal cost curve crosses its marginal revenue curve at an output level of 1 comma 400 units. if the firm produces 1 comma 400 units, its average variable costs equal $6.50 per unit, and its average fixed costs equal $0.80 per unit.

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'

a

b

b

a

c

b

d

d

none of these are correct, as they are all sources of american law

a