Water vapor makes up what percentage of atmospheric gases?
30 percent
10 to 23 percent
0 to 4 percent
20 to 42 percent

The kind of fertilization found in the majority of aquatic animals is (internal or external) fertilization.

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

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above