TASK DEFINITION: Given a scientific question, generate a correct answer to it.
PROBLEM: What bodily defense can be acquired in an active or passive way, and can be natural or artificial?

SOLUTION: immunity

PROBLEM: Inorganic chemistry refers to the study of materials *not* containing which element?

SOLUTION: carbon

PROBLEM: What is heard when sound waves bounce back from a surface that they can't pass through?

SOLUTION:
echo