teeth in the mouth saliva in the mouth enzymes in the stomach enzymes in the small intestine
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What part of the digestive system first causes chemical changes to food?
Possibilities:
- teeth in the mouth
- saliva in the mouth
- enzymes in the stomach
- enzymes in the small intestine

saliva in the mouth