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.

Example Input: Fact: Nephrons are the structural and functional units of the kidneys.
Example Output: Nephrons cause.

Example Input: Fact: a vehicle is used for travel.
Example Output: travel navigation.

Example Input: Fact: decomposition increases the amount of nutrients in the soil.
Example Output:
decomposition animals plant.