<span>Controlled variable is a variable that was made constant in the research. That was because the controlled variables can influence the dependent or independent variable. If the variables is not made constant, it can alter the research result and made it invalid.
In this case, </span>the caffeine and alcohol intake might alter the physical activity or the blood glucose so it should be controlled.
Answer:
A. To enter sulfur dioxide to enter into the cell
Answer:
It is a mixture.
Explanation:
Car battery is mixture because it contain sulfuric acid and water. A mixture is a substance that contain two or more substances which are mixed physically or physically combined and are not chemically combined but can also be separated into the different substance.