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: the mass of a planet causes the pull of gravity on that planet.

Output: earth planet.


Input: Consider Input: Fact: Adult echinoderms have radial symmetry.

Output: echinoderm is starfish.


Input: Consider Input: Fact: Food is easier to chew because it is moistened by saliva from the salivary glands.


Output: bolus saliva.