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: Cells vary in size as well as shape, but all cells are very small.
Output: 


Output:
Cells are functional unit.
Cells in the body are.
Cells.
bacteria cell.
cell size.
cells small microscopic.
cells small.
cells units.
cells vary.
cells very small microscopic.
microscope needed to see cells.
small tiny.