Los seres vivos al transportar sustancias buscan como objetivo la . Con la nutrición y la circulación se pretende que las células obtengan . Los procesos de nutrición y circulación dejan residuos que deben ser eliminados por medio del sistema. Transportar las sustancias a todo el organismo y llevar los desechos hasta los lugares de eliminación se denomina: . La circulación de sustancias desempeña un papel fundamental en equilibrio interno del organismo conocido como: .

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

i hope this : )

maybe because its impossible for balloons to lift a whole entire house.