Question：A __________ establishes a free trade area between member states, and also erects common external tariffs to charge on imports from non-member countries.
What is the missing phrase?
A. Common Market
B. Preferential Trade Area
C. Customs Union
D. Free Trade Area
The correct answer is: Customs Union.
A Customs Union promotes free trade among member states while acting as a protectionist bloc against non-member states.
Question：In some cases, society can gain by restricting imports up to the point at which the benefit of the last import equals its cost to society as a whole. A tariff set to achieve this result is called:
A. A deflationary tariff
B. A welfare tariff
C. A marginal tariff
D. An optimal tariff
The correct answer is: An optimal tariff.
The optimal tariff argument provides a demonstration of the possibility of gains in welfare from a tariff.
，我們將會及時處理。