The definition of price(名词加the 和 加复数的用法）

The definition of price(名词加the 和 加复数的用法）
Prices determine how recources are to be used.They are also the means by which products and services that are in limited supply are rationed among the buyers.The price system of the united states is a complex system composed of the prices of all the products bought and sold in the economy as well as those of a myriad of services including labor,professional,transportation,public-utility services.the interrelationships of all those 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.
以上是从俞敏洪的《英语现代文背诵篇章>中的片断.有关product 和service 有不同的三种用法,1)+the ,2)+the + s 3) 光+S ,
另外包括PRICE 也有多种用法,
名词啥时加 the ,啥时加s .我有点晕...
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