Answer: The Pulmonary Arteries
Explanation: They are two pulmonary arteries with on serving each human lungs, which brings deoxygenated blood to the lungs from the hilium. The arteries go into the capillaries of the alveoli. Capillaries are the thinnest ,smallest blood vessel,they supply oxygen to single tissues in all parts of the human body.
<span>Perhaps surprisingly, lakes and rivers constitute a tiny proportion of the world's total freshwater, so answer (b) is correct. Most of the freshwater on our planet is in fact locked up in ice and glaciers, some 68%. The majority of the rest, 30%, is actually underground, in springs and other groundwater feeders. That leaves just 2% that makes up all the rivers, lakes, ponds and other visible freshwater reservoirs that we see in our day-to-day lives.</span>
Nanoplankton, mesoplankton, megaplankton, picoplankton
If the results of your experiment do not support your hypothesis than you should rework the hypothesis.