英语达人 帮我分析一个句子
问题描述：
英语达人 帮我分析一个句子
some discrepancies have been described between the results of studies performed with a patent-protected formulation of glucosamine sulfate distributed as a drug and those having used glucosamine preparations purchased from global suppliers,packaged and sold over the counter as nutritional supplements.最后一个逗号后面的句子到底是哪个的定语 是those 还是glucosamine preparations的
答
这个句子难以从语法上判别,只能从逻辑上分析.
从定语packaged and sold over the counter as nutritional supplements.看,它修饰的是实物名词,因为只有实物才可以“包装、在柜台销售”（packaged and sold over the counter）,所以修饰对象之能是：drug and those这两个词.这个定语应该对those的补充修饰.