Up to the end of WW II, there we

Up to the end of WW II, there were ______waves of large-scale emigration to the United States.
A、four
B、two
C、three
D、None of the above
【正确答案】：C
【题目解析】：本题考查美国的移民潮。直到第二次世界大战的结束，有三次大规模的移民浪潮涌向美国。