<span>One process wherein diffusion is important is the concentration of salt within a cell. When the salt levels are too high within the cell, salt molecules are moving via diffusion to a region of lower concentration. Another process is the movement of carbon dioxide in plant cells, where CO2 moves from regions of high concentration to regions of low concentration.</span>
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.
Hope this helps :)
Answer:
Explanation:
Oil, coal, natural gas, metals, stone and sand are natural resources. Other natural resources are air, sunlight, soil and water. Animals, birds, fish and plants are natural resources as well. Natural resources are used to make food, fuel and raw materials for the production of goods.
the answer is = A
