What two characteristics of earth allow liquid water to exist?

The optimum temperature and pressure.

Explanation:

The two characteristics that allows the water to remain in the liquid state is the temperature.

The temperature on the earth is very optimum for the water to remain in liquid state. Though some part of the earth has water in the form of ice and glaciers but it can be converted into water.

The pressure on the earth is optimum for the water to remain in liquid state. This is the reason for the water to remains in liquid state.

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.