Why wasnt Oxidation chemical weathering common 2 billion years ago

Oxygen levels were a lot lower then

Explanation:

2 billion years ago was before the Great Oxidation Event. The first oxygen-producing cyanobacteria did not exist before then. Without oxygen, oxidation cannot be common.

protein makes up the building blocks of organs, muscles, skin, hormones and pretty much everything that matters in your body.

some choices are:

peanut butter

seeds

eggs

yogurt

meats

fish

so pretty much meat, dairy, nuts, and grains.