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: Ethologists usually study how animals behave in their natural environment.
Output: 


Output:
Ethologists.
animal behavior can be dangerous.
animal behavior in natural environment.
animals behave.
animals monkey.
environment animals home.
environment habitat.
ethologist scientist.
ethologist.
ethologists.
habitat environment.
natural environment is called habitat.
natural environment.