Granite rough and has ridges
Obsidian more smooth and hard
Pumice red and bumpy
Scoria grey and rough like
Answer:
C.
Explanation:
They will need to know the influence of gravitational force on objects because gravity can affect an objects weight.
Divide measured yield by calculated yield
140/176 = 79.55%
I think the answer is D. the upper surface of undergound water.