Answer:
It is easier to scale the voltage of AC from high to low and low to high than with DC
Explanation:
typically power is used far away from the place where it's generated so to ensure that transmission losses( copper losses) are minimized voltage has to be stepped up during transmission..but due to the fact that most house hold equipment requires low voltage levels it has to be stepped down once it reaches a household/ domestic load...it's easier to do this for Ac than for DC.
Glass on glass,tire on concrete,tire on snow
Condensation, radiation, convection, conduction are many ways heat is transferred from atmosphere to ocean. however heat comes from the sun then, to the atmosphere.