The Aryans are the ones who introduced the Caste System.
Landform regions are like mountains, plains, rivers, etc.
Climate regions are deserts (arid), tundra, tropical, etc.
Hope this helps. :)
Answer:
Speed of sound wave v=νλ=2000×0.35=700 m/s
Distance d=1.5 km=1500 m
Time t=vd=7001500≈2 s
Thermal because you have to melt rocks for rocks to become other types of rocks.
