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.

Input: Consider Input: Fact: telephones are used for communication by two people by transmitting sound.

Output: Sound is waves.


Input: Consider Input: Fact: an electron microscope is used for seeing very small objects by making them appear bigger.

Output: atoms are small.


Input: Consider Input: Fact: if the amount of available food and water decreases in an environment then animals may leave that environment to find food and water.


Output: animals bears.