Human activities that affect natural ecosystems include:

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

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.

silty loam

hope this