请问第三问 What do we know about this country given its supply curve for net imports?
还有第四问的第二小问,The country imposed an import quota equal to half the imports of copper prior to the imposition of the quota?
第三问:small country, changes of domestic supply and demand have no impact on global price.
第四题第二问:mm is domestic price curve without any quota or customs duty, domestic price arises when a quota is set (you can illustrate this effect by graph).