Answer:
Blood is carried away from the heart by arteries. Blood that is rich in oxygen. Blood that is low in oxygen is returned to the heart by veins. there is more pressure in arteries than in veins.
Explanation:
Taking steps to reduce or eliminate pollution from nonpoint sources such as streets and farms will help to maintain the ecological balance. Sewage and run-off of agricultural fertilizer can cause the rapid growth of algae in lakes and streams. The growth of algae blocks sunlight and depletes the oxygen in the water.
Answer:land pollution (i think)
Explanation:
