instruction:
Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
question:
Question: What does the human body produce to help digest food? Answer: enzymes
answer:
The human body produces many enzymes that help digest food. Here are just two examples.

question:
Question: What device is used to stop a current in a circuit? Answer: a switch
answer:
Understand current as it passes through a series circuit.

question:
Question: What occurs when the immune system attacks harmless substances that enter the body from the outside? Answer: allergies
answer:
Allergies occur when the immune system attacks harmless substances that enter the body from the outside.