Which of the following is an example of the respiratory and circulatory systems working together?
A.
The diaphragm flexes, and the lungs take in air.
B.
A virus enters the body, and the white blood cell levels rise.
C.
The blood flows through the kidneys, and waste products are removed.
D.
The lungs take in air, and the blood carries oxygen to the body's cells.
1 answer
D. The lungs take in air, and the blood carries oxygen to the body's cells.
1 answer