We can see a candle flame at 30 miles on a clear, dark night, and we can hear the tick of a watch 20 feet away in a quiet room. These two facts are examples of .

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

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

Match the functions to the cell types ? contraction and relaxation. conducting electrochemical signals fighting diseases carrying genetic material