Answer:
It's important for a scientist to try to hold all variables constant except for the independent variable. If a control variable changes during an experiment, it may invalidate the correlation between the dependent and independent variable. When possible, control variables should be identified, measured, and recorded.
Answer:
down
Explanation:
because gravity come from the center of the earth the gravitational pull, pulls us down.
<span>Meiosis is the prosess in which cells split</span><span />
D because to help preserve environment everyone has to work together
