I believe it is demonstrating caves<span />
Answer:
Plain Tap Water
Explanation:
You should find that plain tap water produces a much larger, stable drop of water on top of the penny than the soapy water does. This is because plain tap water has higher surface tension, so the surface is "stronger" and can hold together a larger drop.
Guanine-Cytosine & Adenine-Thymine
I believe it's the <span>nucleus.</span>
