Which main idea does this detail fit? Fossil fuels are composed mostly of hydrocarbons.

This detail provides the main idea that fossil fuels are rich in carbon and hydrogen.

Explanation:

As seen in the question above, fossil fuels are mainly formed from hydrocarbons. Hydrocarbons, in turn, are organic compounds, widely studied because of their wide use, composed exclusively of carbon and hydrogen atoms.

For this reason, when someone claims that "Fossil fuels are composed mostly of hydrocarbons" we can consider the main idea that fossil fuels have a large amount of carbon and hydrogen in their composition, which explains the ability to combust that these fuels have.

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

human-caused climate hope this