The United States of America is

The United States of America is an ethnically and racially diverse country as a result of _______.
A、large-scale migration
B、mass communications
C、sprawling cities
D、a high birth rate
【正确答案】：A
【题目解析】：【考点点击】本题主要考查美国文化。
【要点透析】美国是一个由移民组成的多种族、多元化的国家。P248