Thus, in the American economic system it is the demand of individual consumers, coupled with the desire of businessmen to maximize profits and the desire of individuals to maximize their incomes, that together determine what shall be produced and how resources are used to produce it. 句子主干: it is the demand of ...， coupled with the desire of ...and the desire of ... that .... 结构分析: 这是一个强调句。coupled with 是 the demand 的后置定语。 determine 后有一个what 引导的宾语从句和一个。how 引导的宾语从句。 [参考译文] 因此，在美国的经济体系中，个体消费者的需求与商人试图最大化其利润的欲望和个人想最大化其收入效用的欲望相结合，一起共同决定了什么应该被生产制造，以及资源是如何被用来生产制造它。