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.
One example is below.
Q: Fact: pesticides cause pollution.
A: pollution harms.
Rationale: This is a good topic word, because it contains one overlapping word "pollution".
Q: Fact: Echinoderms lack a centralized nervous system.
A:
Echinoderms sand dollar.