Definition: Given a statement and question, generate the answer to the question such that the answer is contained in the statement.

Positive Example 1 -
Input: statement: Neurons deliver electrical impulses to other cells, question: What do neurons deliver to other cells?
Output: Electrical impulses

Positive Example 2 -
Input: statement: Two lenses to produce magnified images allow for detailed observation of stars., question: Two lenses to produce magnified images allow for what?
Output: Detailed observation of stars

Negative Example 1 -
Input: statement: Two lenses to produce magnified images allow for detailed observation of stars., question: Two lenses to produce magnified images allow for what?
Output: Barack Obama

Negative Example 2 -
Input: statement: Sharks have sharp jaws to catch their prey, question: What do sharks have to catch their prey?
Output: Sharp claws

Now complete the following example -
Input: statement: an optical system is used for observing stars by researchers, question: What is used for observing stars by researchers?
Output: 


Output: an optical system