Earth's early atmosphere was primarily composed of hyrogen cyanide and carbon monoxide.

oxygen and carbon monoxide.

oxygen and water vapor.

carbon dioxide, water vapor and nitrogen.

the answer is: trichonympha lives in the gut of termites and digests cellulose eaten by the termite.

this is an example of a symbiotic association of a protozoan with its mode of association.

hope i

-lavira: )

sex cells are usually half's then they find another half and make a fertilize egg