TASK DEFINITION: In this task, you're given an ambiguous question (which can be answered in more than one way). Your task is to write a question that clarifies the given question in such a way that the generated question has one unique answer.
PROBLEM: Raised line markers on the roadway and shoulder are used to define?

SOLUTION: Raised line markers on the roadway and shoulder are, parallel to drive directed are used to define?

PROBLEM: Who is the father of emma on friends?

SOLUTION: Which character is the father of emma on friends?

PROBLEM: What episode did izzy leave grey's anatomy?

SOLUTION:
What episode did izzie leave grey's anatomy?