What name is given to a discrete packet of light

At which location in earth’s interior does the top density continue to increase as thickness decreases?

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

Ture or false evidence for evolution includes millions of fossils