Blood? I think cause it flows through everything in the body
<em><u>A.SURFACE </u></em><em><u>RUNOFF</u></em><em><u> </u></em><em><u>FROM </u></em><em><u>RAIN.</u></em>
<em><u>C.MELTING</u></em><em><u> </u></em><em><u>ICE</u></em>
<em><u>B.OCEAN </u></em><em><u>CURRENTS </u></em><em><u>(</u></em><em><u> </u></em><em><u>I </u></em><em><u>guess?</u></em><em><u>)</u></em>
<em><u>[that's it]:)</u></em>
Nucleic acid<span> typically contain phosphorous, and nitrogen plays an important structural role in nucleic acids and proteins. The proteins, being made up a diverse set of amino acids, have, in addition to carbon, hydrogen, oxygen, and nitrogen, the elements sulfur and selenium.</span>
An isotonic solution is a solution in which the amount of dissolved material is equal both inside and outside of the cell. Water still flows in both directions, but an equal amount enters and leaves the cell. Hope this helps. :)
The answer should be rain water