Answer:
i willl answer this science question in the comments section
Explanation:
Following glycolysis, the mechanism of cellular respiration involves another multi-step process—the Krebs cycle, which is also called the citric acid cycle or the tricarboxylic acid cycle. The Krebs cycle uses the two molecules of pyruvic acid formed in glycolysis and yields high-energy molecules of NADH and flavin adenine dinucleotide (FADH2), as well as some ATP.
<span>The voyage of the HMS Beagle is led by the scientitst
Charles Darwin in search for species around the globe and a curious observation that led him to
theorize about evolution. It leaves form Plymouth Harbor, toured around the
Madeira and Canary islands and made a landfall at the Cape of Verde islands. The
expedition was originally planned to end in two years. It got delayed and
turned into five years due to Darwin spending most of his time exploring on
land. the answer is D.</span>
I beleive it might be a Hydrogen molecule but I am not 100% positive of this.