Which of the following best describes a passive ventilation system? a system using fans to move heated air around and out of a greenhouse

a system using the natural motion of air through heated pipes in the floor to circulate heat

a system using tubes suspended from the ceiling to move heated air to specific locations

a system using the natural motion of air through vents to remove hot air from a greenhouse

Digestion because it removes waste

The return of the wolf to yellowstone national park will probably affect the bird population to some degree, not significantly. while wolves will hunt birds when necessary, they prefer to hunt larger prey. the bird population will most likely only be affected when hunting is scarce for the wolves. birds of prey will also probably not be affected as much as other birds who spend more time on the ground hunting for food as the tend to spend more time in the air or in trees since they do not need to stay on the ground for long due to the nature of the way they hunt.

A.true this might be wrong, but if it's not wrong, mark me brainliest.