A graph that can be used to visualize or systematize the generation of ideas based upon a certain topic.
Muscle contractions in your lower legs act as pumps, and elactic vein walls help blood return to your heart. Tiny valves in your veins open as blood flows toward your heart then close to stop blood from flowing backward. Causes of varicose veins can include: Age
Answer: B) No one knows what causes asthma, but family history is certainly influential.
Explanation:
The corrcet answer would be relational.
