Which of these was a result of the columbian change

The primary positive effect of the Columbian exchange was the introduction of New World crops, such as potatoes and corn, to the Old World. The most significant negative effects were the transmission of African populations into slavery and the exchange of diseases between the Old and New World.

New lives were possible in America for the poor Europeans

the dominoes began to fall. the surrender at appomattox took place a week later on april 9. while it was the most significant surrender to take place during the civil war, gen. robert e. lee, the confederacy's most respected commander, surrendered only his army of northern virginia to union gen. ulysses s. grant

explanation:

explanation:

the addition to geographic boundaries that might have  kept the people of the huang river civilization from traveling to far distance region is that they had learned about the other river valley civilizations but feared contact would bring invasion.

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