I'd say b, but i'm not 100 percent sure.<span />
<span>The human body is organized at different levels, starting with the cell. Cells are organized into tissues, and tissues form organs. Organs are organized into organ systems such as the skeletal and muscular systems.</span>
<span>True. Acid rain is formed when compounds released during the burning of fossil fuels, such as sulfur dioxide and nitrous oxide, dissolve in water droplets in clouds. These then fall as rain as part of the water cycle. While some rain is naturally acidic, human activities, like burning fossil fuels, have made it worse.</span>