What this student is doing is collecting data. So, he wants to check how many life forms there are in the waters nearby. In order to do so, he has to take a sample, and look at it through a microscope so as to determine the number. So, he collected a sample which is his data. He is not drawing conclusions yet, but rather counting these organisms. He is not making a peer review - his peers aren't even mentioned here. He is not forming a hypothesis because he is just counting at this point.
The inferior vena cava brings deoxygenated blood back into the heart from the lower body. For comparison, the part that directs deoxygenated blood from the upper body is the superior vena cava.
