【单选题】France and England both produce wine and cloth with constant opportunity costs. France can produce 150 barrels of wine if it produces no cloth or 100 bolts of cloth if it produces no wine. England can...
【单选题】France and England both produce wine and cloth under conditions of constant opportunity costs. France can produce 150 units of wine if it produces no cloth, and 100 units of cloth if it produces no wi...