TASK DEFINITION: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
PROBLEM: Category: SCIENCE GRAB BAG 
Clue: A material called URhGe can be manipulated into being this, lacking electrical resistance

SOLUTION: superconductors

PROBLEM: Category: PARADISE LOST 
Clue: Completes the famous line from Book I, "Better to reign in hell, than..."

SOLUTION: serve in heaven

PROBLEM: Category: WE ARE THE CHILDREN 
Clue: Of this composer: 20(!) of us, including 5 Johanns & 2 Johannas

SOLUTION:
johann sebastian bach