【正确答案】 A

【答案解析】[听力原文] Jessica: Good morning, class. Today we have Professor Wilson here to tell us something about free trade. Professor Wilson: Well, free trade means no tariffs and no quotas between countries that trade goods with one another. But, it's not only a free flow of goods. It also means the free flow of services between nations. It's a system that allows people to buy and sell whatever they desire with whomever they desire. Advocates argue that total free trade will result in a net gain in wealth for both trading partners. Some of the characteristics of free trade are...uh, let me list them for you. First, the absence of tariffs, which are taxes on imported goods and services. Second is the absence of quotas and other trade barriers. Third, the free flow of labor between two trading partners. Fourth, the free flow of capital between the two trading partners. And fifth is the absence of subsidies and regulations on locally produced goods and services that give businesses in the home country an advantage over those of a foreign country. Now having said all this, keep in mind that free trade is a relatively loose term that means different things to different people. For instance, it can be any combination of these characteristics I just mentioned to you, and, typically, it's never completely 100% free. When you have a free trade agreement between two countries, there are usually some protective policies in place. Protectionism, on the other hand, means government restraint on trade between two nations. Protective trade or protective tariffs are a nation's efforts to prevent its own people from trading. Such protective measures include tariffs on imported goods and services, restrictive quotas on imported goods and services, government regulations which discourage imports, anti-dumping laws, and subsidies for local producers. There are a number of advantages to free trade. Perhaps the most important advantage of free trade is that it lowers the costs of goods and services. This is possible for a number of reasons. For example, production can take place in nations where labor and other operating costs are lower. Despite its apparent advantages, there are a number of critics of free trade. Many people prefer protectionism. And, as I mentioned a moment ago, in the real world, even when we have free trade or a free trade agreement, there's still some protectionism. Protectionists feel it's better for local consumers to pay higher prices and thereby maintain quality jobs. So, protectionism protects businesses, jobs, and wages, but it also means higher prices. Why do some people approve of total free trade? 关于一些人支持自由贸易的原因，听力原文中提到Advocates argue that total free trade will result in a net gain in wealth for both trading partners. 由此可知，支持自由贸易的人认为绝对的自由贸易可以让交易双方都获得净利润。由此可知，A项正确，故选A。

【正确答案】 D

【答案解析】[听力原文] Why does a nation impose protective tariffs? 听力原文中提到Protective trade or protective tariffs are a nation's efforts to prevent its own people from trading. 由此可知，贸易保护或者保护性关税是一个国家限制进口，从而保护其国内产业不受影响而采取的措施，因而D项表述正确，故选D。

【正确答案】 C

【答案解析】[听力原文] What could be the most important advantage of free trade? 关于自由贸易最重要的好处，听力原文中提到Perhaps the most important advantage of free trade is that it lowers the costs of goods and services. 由此可知，自由贸易最大的好处可能在于它降低了商品和服务的价格，C项表述符合原文，故选C。

【正确答案】 D

【答案解析】[听力原文] What's the benefit of protectionism? 听力原文最后提到了贸易保护主义的好处，即protectionism protects businesses，jobs，and wages，指出贸易保护主义保护了企业、工作和薪酬，因而D表述符合原文，故选D。