Human bone does not contain oxygen
Independent is what you are testing with. dependent is what you ARE testing. constant is the control so like for example the time, or the same material etc. tools should be on your paper depending on what lab it is :)
Animals need oxygen to produce energy for their bodies. The living parts of<span> an </span>ecosystem are animals<span>, plants, </span>fungi<span>, protists, and bacteria. These organisms make up the BIOTIC factors of an </span>ecosystem<span>. </span>Ecosystems<span> are made up of biotic and abiotic components.
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