Identify what all organic compounds have in common, and list the four principal classes of or organic compounds

Carbon, Hydrogen, Oxygen, Nitrogen

Explanation:

The most common elements present in organic compounds are carbon, hydrogen, oxygen, and nitrogen. With carbon and hydrogen present, other elements, such as phosphorous, sulfur, silicon, and the halogens, may exist in organic compounds.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs

i think that you are smart and you should fit for it out