What were two differences in immigration patterns between the years 1900-1960 and the years 1970-1990?

a plantation economy is an economy based on agricultural mass production, usually of a few commodity crops grown on large farms called plantations. plantation economies rely on the export of cash crops as a source of income.

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the correct answer is c. a piece or imprint of something that was once alive

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europeans carried a hidden enemy to the indians: new diseases. native peoples of america had no immunity to the diseases that european explorers and colonists brought with them. diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to american indians