....................I’m really not sure but c
Explanation:
Convection occurs in the Earth's mantle because it is the most efficient way for the Earth to cool or dispose of its deep-seated heat content. In general, heat can be transferred by conduction, radiation or convection.
Answer:
Because Mexico–U.S. migration represents the largest sustained migratory flow between two nations worldwide, much of the theoretical and empirical work on migration in the Americas has focused on this single case. Yet in the past few decades, migration has emerged as a critical issue across all nations in Latin America and the Caribbean. Indeed, over the past fifteen years, this region has changed its historical position from a net migrant-receiving region to one of the leading sending areas of the world.
