Answer: the second one " the seasons are caused by the tilt of earth's axis and how much solar radiation each area of earth receives. "
Explanation:
i took the test on k12.
Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere. Power plants release the majority of sulfur dioxide and much of the nitrogen oxides when they burn fossil fuels, such as coal, to produce electricity. In addition, theexhaust<span> from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air. These pollutants cause acid rain.</span>
I'm pretty sure (C) Nitrogen is a compound.
