How many types of amino acids are there

(6.02 mc)what affect do marine protected areas have on environmental quality? they increase environmental quality by preventing resource overuse. they increase environmental quality by adding new species. they decrease environmental quality by removing all human activity. they decrease environmental quality by adding recycling facilities.

If 360 joules of work are needed to move and create a distance of 4 m what is the weight of the crate

The earth formed roughly 4.5 billion years ago, yet evidence of life dates back to about 3.5 billion years ago. which one is not a possible hypothesis of how life on earth arose?