Suppose the US and Mexico both produce semiconductors and auto parts and the US has a comparative advantage in semiconductors while Mexico has a comparative advantage in auto parts. Also suppose that the US has an absolute advantage in the production of both semiconductors and auto parts. The US should

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.'