Which of the following is our major source of energy

Are the earth's ocean floor and continents the same age geologically? why or why not?

The tubes transporting minerals and water upward are called ?

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