Step-by-step explanation:
1) %70 earth is water and %30 is land.
2)" The single cells in the brain communicatethrough electrical and chemical signals.
3) b'coz earth revolve around the sun in365 days and rotates on its axis in 24 hours. It takes 365 days , because it takes that much time to complete one revolution and it takes 24 hours,because it takes time to complete one rotation as mercury takes 81 earthdays to complete one revolution.
4) Human originated from Adam And Eve.