The correct answer is option B, hydrogen.
The majority of the atmospheric gases are found in the sea water solution. In supplementation to oxygen and nitrogen, the most profusely found gas in the atmosphere, that is, carbon dioxide is found in the ample concentrations in the ocean waters.
However, hydrogen is not present, and if found it is found in minute concentration. Of the gases, nitrogen is the most abundant gas found in seawater, while oxygen is the second most abundant, and carbon dioxide is the most soluble gas, and one of the various constituents, which influences the pH balance of the ocean.
An indicator species<span> is an organism whose presence, absence or abundance reflects a specific environmental condition. </span>Indicator species<span> can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem.
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Microscopes allowed scientists to observe Prokaryotic cells which make up Bacteria and Archaea. These cells are small and contain no membrane- bound organelles. It allowed them to observe Eukaryotic cells with a nucleus and membrane-bound organelles that perform different life functions.
B press a clean towel or cloth firmly against the cut. you don't want the bleeding to continue and don't want to make the cut worse by putting any liquid in a lab, like acid that could easily be mistaken as water.