Answer:
Q. 61 True, Q.63. True Q.64. True Q.66. 71%
Explanation:
its provided in the richter scale that the earthquakes of magnitude of 4 occur every 10,000 times in a year.
Orogenesis is a process of mountain building through the formation of ocean basins and plate tectonics.
The continental crust or the plates are composed of SIAL i.e SIlicon and aluminium i.e light and less dense than the below oceanic plates.
Majority of the earth is made up of water i.e 71 percent and rest 29% is water i.e Land vs Water ratio.