What type of biomolecule would you want to have if you were swimming across the english channel

the fossil record provides evidence of a common ancestor to many species.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

the answer is d p: cell, q: organ, r: organ system, s: tissue