Teeth break food into small pieces. Throat muscles push food toward the stomach. Stomach acids dissolve food into nutrients. Intestinal cells transport nutrients into the blood.
I gave my students this multiple choice question: Which part of digestion is mainly a chemical change?

Only one answer is correct among these 4 choices:
- Teeth break food into small pieces.
- Throat muscles push food toward the stomach.
- Stomach acids dissolve food into nutrients.
- Intestinal cells transport nutrients into the blood.

Could you tell me which one is correct?

Stomach acids dissolve food into nutrients.