单项选择题
Between 1845 and 1854,about 1.5 million Irishmen emigrated to United States because of（）
A.famine B.English oppression C.war D.Both A&B
单项选择题 Up to the end of WW II,there were（）waves of large-scale emigration to the United States.
单项选择题 The population between the age of 25 and 44 increased by 28.1%from 1980 to 1989 because（）
单项选择题 More than（）of the population in the United States lived in city areas in 1988.
