Question 3 The diagram below represents a stack of rock layers. Examine the diagram, and answer the question that
follows.
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4
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2
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What do these layers and their fossils suggest about Earth's history?
A. There have been changes in Earth's lifeforms over time.
B.
Only one kind of lifeform lived where these layers formed.
c. Lifeforms on Earth have been the same over time.
D. No lifeforms were present when these layers formed.
Question 4

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

youre right there are

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.