The four main elements in food that energy to move from one trophic level to another is

Carbon, Hydrogen, Nitrogen, and oxygen  

Explanation:

Trophic levels are the way ecology uses to organize the organisms that make up a food chain, where mass and energy transfer occurs between individuals or populations. The components of these chains can be simplistically divided into three broad groups: producers, consumers and decomposers. Foods that are involved in trophic levels have as their main elements carbon, hydrogen, nitrogen and oxygen. These elements are present at all trophic levels and are responsible for helping energy move from one trophic level to another.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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