B. Soil Contamination
All the other answers are talking about clean and pure things while this answer is the only negative one. So B is your answer.
Answer:
<em>Humans cultivate plants that house bacteria in soil to convert ammonia and ammonium ions to </em><u><em>nitrate</em></u>
Explanation:
Ok on the first question I have no clue but on the second question of going to be the last answer white with a few grey
Answer:
Plants extract energy from food molecules the same way animals do — by cellular respiration. When plants do cellular respiration, they produce carbon dioxide and use oxygen just like animals do