I believe the answer to this question is D, I am not sure though.
Answer:
Essay on types of digestion
Explanation:
Digestion refers to the breakdown of large food molecules into small food molecules so that can be absorbed by the blood. There are two types of digestion i. e. mechanical digestion and chemical digestion. in mechanical digestion, the food is broken down into smaller parts physically with the help of teeth while on the other hand, in chemical digestion, food is broken down into small particles with the help of chemicals such as acids and enzymes. This chemical digestion is carried out in the stomach where different types of chemicals are present.
Coal, oil, and, natural gas
The independent variable controls the dependent variables.
