Answer:
"Wood is technically a renewable source of energy, since it is a form of biomass. All biomass is traditionally considered a renewable source of energy because it is part of the natural carbon cycle on Earth." I found this from https://www.quora.com/
Explanation:
1A: The legs can be a adjusted, as well as the sand can be swapped out. It’s a very good design for running multiple tests.
1B: He could add books or something under the front or back legs in order to increase/decrease the incline, therefore imitating the hypothesis.
1C: He can change out the sand grains to finer ones, or coarser ones, and record his results of each test.
2: If he sets the model at a steep incline and tests it with coarse sand and fine sand, seeing which one makes a narrower, deeper hole.
Alkali are soluble bases, however not all bases are soluble in water, therefore not all bases are Alkali.
