Producing one yard of cloth requires 3 worker and 1 capital, while producing one pound of food requires 1 worker and 2 capital. Both countries have 720 workers; the United States has 480 capital, while ROW has 720. The price of food is always $24/pound; the price of cloth is $22/yard in the United States in autarky and $32/yard in both countries under free trade. The labor constraint is a. QC + 2QF = 720
b. QC + 3QF = 720
c. 2QC + QF = 720
d. 3QC + QF = 720
e. none of the above

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. primarily outdoors, responding to emergencies and protecting people.

have a nice day!