Answer:
C. 140 years
Explanation:
Undergoing decay to decrease by half.
This should be under mathematics not geography.
Answer:
D
Explanation:
Isostasy is the condition of equilibrium that results in the displacement of the mantle by the continental and oceanic crust.
Isostasy is also known as standstill. It is the condition that makes earth's crust and mantle to float dependin on the thickness of the roots.
It is knowing as stellar evolution