Answer:
Yes, they are secondary consumers, who sometimes eat phytoplankton
Explanation:
Answer is: the part of an experiment that stays the same though out the experiment is constant.
<span>Constant is a quantity that does not change.
</span>Experimental variable<span>, which is the also part of an experiment, is affected by the experiment (have change).</span>
<span>main function of the circulatory system in multicellular organisms is to circulate blood and oxygen in our body .so the right option is
</span><span>A) to bring oxygen into the lung
</span>hope this helps