Unlike other plants, trees are plants living for several years thus they are A. Annual

B. shade

C. perennial

D. Fence

hello there the answer is d

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.