Carbon,hydrogen,oxygen and nitrogen :)
The <span>Phranerozoic represents the past 544 million years of geologic time</span>
1. The ETC (electron transport chain) produces most ATP so C
2. I'm not exactly sure, but whenever there is less oxygen, fermentation takes place. I'd go for A,but you might want to check ur lessons or something.
C. physiological
Because the teeth becoming sharper is a physical change .