Loss of Arctic ice affects the sustainability of human population negatively. Arctic ice helps cool the planet down as 80% of light that hits it is reflected. Extreme temperatures as well as a list of other affects of climate change hurt the sustainability of human populations.
This question would be better placed under the Chemestry section
Answer:
Students who take a PE class and who will be eating sugary snacks before PE.
Explanation:
The control variable (or control group) is an experimental element which is constant or unchanged throughout the course of the experiment.
The option "students who take PE class and who will be eating sugary snacks before PE" will remain unchanged and constant because the whole point of the experiment is to see the effects on students performance in PE after eating sugary snacks.
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