instruction:
Given a statement and question, generate the answer to the question such that the answer is contained in the statement.
question:
statement: Muscles in the upper arm lengthen a person's elbow., question: What lengthens a person's elbow?
answer:
Muscles


question:
statement: Parts on the leaves and stems close to reduce moisture loss., question: Parts on the leaves and stems close to reduce what?
answer:
moisture loss


question:
statement: Muscles contracting makes a person's elbow straighten., question: What kind of elbow is straightened by a person's contracting of muscles?
answer:

elbow