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.

Fact: melting means changing from a solid into a liquid by adding heat energy.
fire heat energy.

Fact: when a gas in an open container evaporates , that gas spreads out into the air.
air contamination.

Fact: Pollen consists of tiny grains that are the male gametes of plants.

Pollen.