2014-2015学年高中英语（精品）同步
教案（第7课时）：unit 1 a land of diversity人教新课标选修8）
文化背景知识
the united states
background:
britain’s american colonies broke with the mother country in 1776 and were recognized as the new nation of the united states of america following the treaty of paris in 1783. during the 19th and 20th centuries, 37 new states were added to the original 13 as the nation expanded across the north american continent and acquired a number of overseas possess
