Yes they did. It is generally known that amphibians breathe through their skin.
Answer:Muscle cells are able to produce ATP with oxygen, which is called aerobic respiration, or without oxygen, an anaerobic process called anaerobic glycolysis or fermentation. The process in which ATP is made is dependent on the availability of oxygen (see the Cellular Respiration concepts).
Explanation:
3) grass and pine cone
4) lemming, rabbit, insect, squirrel, deer, caribou and moose
5) badger and bear
6) wolf, snowy owl, hawk, fox and ant
7) lemmings would die out because they have no other food source
A light year is the distance traveled by light in a year.