What is the agricultural revolution. just a little definition plz

Why does physical weathering speed up the processes of chemical weathering? a) physical weathering requires abundant water, as does chemical weathering. b) physical weathering produces fresh surfaces for chemical weathering to attack. c) chemical weathering can occur only on small surfaces, not large ones. d) chemical weathering requires salt, which is provided by salt wedging.

How did the europeans design the national borders of africa? why?

What is the general rule about surface currents? cold water flows along the ocean floor towards the equator. the east coasts of continents have cold surface currents, and the west coasts of continents have warm surface currents. seasonal and constant offshore winds create significant upwelling along the west coasts of south and north america and africa. the west coasts of continents have cold surface currents, and the east coasts of continents have warm surface currents.