TASK DEFINITION: Given a scientific passage and an answer, generate a question for the given answer.
PROBLEM: Passage: When a fluorine atom gains an electron, it becomes a negative fluoride ion. Answer: fluoride ion

SOLUTION: When a fluorine atom gains an electron, it becomes a negative what?

PROBLEM: Passage: Power plants are where electric power originates. They have electric generators that generate electric current through electromagnetic induction. Answer: power plants

SOLUTION: Where does electric power originate?

PROBLEM: Passage: A changing magnetic field produces an electric current in the process of electromagnetic induction. Current is generated whenever an electric conductor crosses magnetic field lines. Answer: magnetic field lines

SOLUTION:
What does an electric conductor cross to generate current?