Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.

Answer:
1. A flood could damage houses with causes gas leaks, which isnt good for animals and the enviroment.
2. A flood is bad for animals, and animals/trees keep the ecosystem alive.