Answer and Explanation:
Rectum
The answer is the Rectum.
This is where everything is stored after all the processes.
<em><u>#teamtrees #PAW (Plant And Water)</u></em>
In some capacity, earth scientists study all of the above listed. They focus on ecology (how different organisms function within ecosystems), food chains, climates and weather patterns, aspects of the atmosphere, soil and the Earth's mineral components, farming, and how man's machines both help and hurt the environment.
Get twenty people, from various genders and ages, to be your testees. Create a random test that has both analytical and logical problems, and get the 'testees' (I have no idea if this is a word or not) to do the test before and after spending time outdoors.
An independent variable is how much time they spend outside, and the dependent is how well they function afterwards. (I think).
The constant is what stays the same, so most likely the tests in this case (if taking my example)
I don't really know what you mean by control, though...
This is what I would've done if it was my homework assignment, I'd suggest looking over my answers to see if they're accurate or not. Hope I helped, and good luck.