1011517: most of the children were African American(83%) and male(53%), and all resided in a mid-size urban community in
问题描述：
1011517: most of the children were African American(83%) and male(53%), and all resided in a mid-size urban community in the united states.
想知道的语言点：
1—a mid-size urban community：怎么翻译?
2—united states：怎么翻译?
答
1、中型城市社区,或中型城市居住区
2、美国 简写是US