9、Prices determine how resources are to be used.They are also the means by which products and services that are in limited supply are rationed(定量配给)among buyers.The price system of the United States is a complex network composed of the prices of all the products bought and sold in the economy as well as those of a variety of services， including labor， professional， transportation， and public services.The interrelationships(相互关系)of all these prices make up the “system” of prices.The price of any particular product or service is linked to a broad， complicated system of prices in which everything seems to depend more or less upon everything else.

答案：答：价格决定资源如何使用。同时，由于产品和服务的供应有限，价格还是在消费者之间合理调配这些产品和服务的一种手段。美国的价格体系是一个复制的网络，既包括国民经济中进入买卖的所有产品的价格，也包括种类繁多的服务价格，如劳务服务、专业服务、运输服务以及公共服务等。以上各种价格之间的相互关系，构成了整个价格体系。任何一种特定产品或服务的价格都同一个广泛而复杂的价格体系有关。在这一体系中，任何东西同其他东西似乎多多少少都构成相互依赖的关系。