One type of density change is mass over volume.
Answer:Mitochondria
Explanation:Mitochondria is the powe house of a cell
Answer: Frictional Force
Explanation: Friction always acts to oppose any relative motion between surfaces. For the simple example of a book resting on a flat table, the frictional force is zero.
The answer to the first question is (A) from 1 to 2 to 4.
The answer to the second question is (C) Illustration A.
