参考答案

正确答案：D
解析：有关来美国的原因见“In all of American history，less than l0 percent of immigrants have come for political or religious reasons. Economic immigrants from Europe，Asia，and Latin America have come to the United States voluntarily. Others. most African Americans，were involuntarily transported to North America to do forced labor or to be sold as slaves.”这几句，从中没有发现D项，所以排除。