if the firms in a competitive price-searcher market are earning zero economic profit, this indicates that the a. market is not in long-run equilibrium. b. firms are earning the normal rate of return. c. firms are performing worse than the firms in other markets. d. firms are performing better than firms in other markets.

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.'

750 h and costs $0.60 per bulb.

answer; yield to maturity;