The Richter scale is a way of giving the intensity of all earthquakes a numerical value. this allows the strengths of different earthquakes to be compared. Because of this, i think the best answer is D
When a biologist counts the number of zebras in a population each year and notices an increase in the zebra population, this would be an example "of <span>observation"</span>
Its known as the cognitive neuroscience
The oxygen atoms i believe is the answer
-it transports nutrients in the body
-it circulates macrophage in the body
