The earliest atmosphere on earth was composed of A. Oxygen, carbon dioxide and nitrogen

B. Carbon dioxide steam nitrogen nothing and ammonia

C. Hydrogen and helium

The green colored pigment in chloroplasts is? a. nitrogen b. chlorophyll c. chlorophorm d. chlorofloromethane

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?