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: Some viruses have an envelope of phospholipids and proteins.

Output: envelope phospholipids and proteins.


Input: Consider Input: Fact: Amphibians have permeable skin that easily absorbs substances from the environment.

Output: Amphibians skin.


Input: Consider Input: Fact: Flowing water can slowly dissolve carbon in sedimentary rock.


Output: flowing water fall force.