How did adding the wolves help the ecosystem of the park?

these predators have helped parts of the ecosystem bounce back. They've significantly reduced elk herds, opening the door for willow, aspen, beaver and songbird populations to recover

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.