Answer: "pheromones" .
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<u>Note</u>: "Odorless chemicals" that serve as "signals" to members of one's own species are called: <u> pheromones </u><u /> .
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- <em>yes </em><em>I </em><em>agree</em>
<h2><em>hope</em><em> it</em><em> helps</em></h2>
<span>D. They are written in the format of a business letter.</span>
