问题如下：
Which of the following statements about the Ricardian trade model is least accurate?
选项：
A.The Ricardian trade model uses labor as the only factor of production.
B.A country may capture more of the gains from trade if the terms of trade are closer to its partner’s autarkic prices than to its autarkic prices.
C.A country may capture more of the gains from trade if the terms of trade are closer to its autarkic prices than to its partner’s autarkic prices.
解释：
C is correct.
A country gains if trade increases the price of its exports relative to its imports as compared to its autarkic prices, i.e. the final terms of trade are more favorable than its autarkic prices.More generally, a country captures more of the gains from trade the more the final terms of trade differ from its autarkic prices.
考点：Ricardian mode
解析：李嘉图模型认为劳动力是生产中的唯一要素。A选项不入选。
贸易条件指数=出口价格指数/进口价格指数X100%
A国 小麦 10元 牛仔裤100元
B国 小麦 20元 牛仔裤50元。
假设A国12元出口小麦到B国，进口80元价格牛仔裤。 贸易条件0.15
假设A国16元出口小麦到B国，进口50元价格牛仔裤。贸易条件0.32
显然第二中情况下，A国的收益更大。因为它出口的商品更贵，进口的商品更便宜。
好，那么我们再来算一下封闭状态下两国的牛仔裤与小麦的价格之比。A国是0.1,B国是0.4.
那是A国的贸易指数越接近0.4他的获利就越大。0.4代表什么？0.4就代表封闭状态下贸易对手国的两个商品的比价。
这也说明最好麦我以20元出口给B国，而牛仔裤以50元价格从B国进口。此时A国获得收益就是最大的。而此时的贸易条件就是0.4
如果A国以10元的价格，出口小麦，以100元的价格进口牛仔裤，那么他从贸易中获得收益就是0。此时的贸易条件就是0.15
由此可见，本国的贸易条件要尽量和对手国封闭状态下商品价格之比接近才能获取利益。
C选项说反了，所以入选。
老师，A选项怎么理解？ 它跟李嘉图模型中认为促进经济增长的是labor productivity（即technology）有啥联系和区别？
