i visited the museums and sat in public gardens 上句中为何museum和garden的后面要加s?

题目

i visited the museums and sat in public gardens 上句中为何museum和garden的后面要加s?
还有这个例子America and Americans were prosperous beyond the dreams of the Europeans and Asians whose economies the war had destroyed..其中的european和asian后面也加了s，只是为了形容很多欧洲人和亚洲人吗？

答案

因为“我”参观了多个“博物馆”和“公园”的啊,只要大于1个（2个及以上）就要用该名词的复数形式,所以用museums/public gardens