In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.
--------
Question: Fact: coal is used to produce electricity by burning in coal-fire power stations.

Answer: Electricity is energy.


Question: Fact: Ants communicate with chemicals called pheromones.

Answer: ant insect.


Question: Fact: a telephone is used for communication by humans over long distances.

Answer:
communication convey.