Definition: 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.

Positive Example 1 -
Input: Fact: pesticides cause pollution.
Output: pollution harms.

Positive Example 2 -
Input: Fact: pesticides cause pollution.
Output: modern farming pesticide.

Negative Example 1 -
Input: Fact: pesticides cause pollution.
Output: computer harms.

Negative Example 2 -
Input: Fact: pesticides cause pollution.
Output: toopaste helps.

Now complete the following example -
Input: Fact: Many corals secrete an exoskeleton that builds up to become a coral reef.
Output: 


Output:
coral exoskeleton is made of carbonate.
coral reef.
coral secrete build.
coral.
corals secrete exoskeleton.
exoskeleton.
fish make homes in coral reefs.
invertebrates coral.
reef.