theories of free trade的用法和樣例：
例句
- Europe is the birthplace of free trade theory, and the E.U. is the product of successful free trade practices.
歐洲是自由貿易理論的誕生地，歐盟是自由貿易的成功典范。 - As the traditional trade theory tells us that free trade is the best trade policy, the STP is totally conflict to it.
從而打破了傳統貿易理論下自由貿易才是最佳貿易政策的說(shuō)法。
