Another example of how difficult it is to categorize people involves populations in the U.S.
Another example of how difficult it is to categorize people involves populations in the U.S.
分类人群极为困难，另一个例子是各种族裔都有的美国人。
Another example of how difficult it is to categorize people involves populations in the U.S.
分类人群极为困难，另一个例子是各种族裔都有的美国人。