Why did large numbers of african migrate to the americas

Drastic boundary changes can occur for all of the following reasons except for a. a shift in the way a river flows b. the collapse of a government system c. a conflict between two neighboring groups d. one country's decision to sell land to another country select the best answer from the choices provide

Which of the following best describes asbestosis?

The middle east links which two continents? ●asia and europe●europ and africa●africa and asia●africa and australia