Exposed rocks are mechanical since it is exposed to the outside elements a.k.a the weather and it's wearing down it's composition naturally,it would be chemical if you dropped into a solution or something to alter the rocks composition...hope this helps.
The hypothesis of continental drift is used to explain an event that happened
a. two million years ago.
b. two hundred million years ago.
c. two billion years ago.
d. two hundred billion years ago.
The answer is (b) Two hundred million years ago
Answer: A). 2.7 million people per year
Explanation:
From 2000 to 2010 is 10 years. Change in population in 10 years = population at the beginning of 2010 minus the population at the beginning of 2000. This is:
309 million -282 million = 27 million.
Therefore average change in population person year = 27 million/10 = 2.7 million per year