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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Answer:
I think it's D, but it could be B.
Explanation:
That way they can get the average result and they're usually more accurate.
Not sure but I think motor systems?
-Wulf
