- All living things are made of cells according to the cell theory
- If something is made of something else, then that something contains at least one of that something else
- Hence, all living things contain at least one cell

So, all living things contain at least one cell
Which statement about all living organisms is true?
- All living things are made of cells according to the cell theory 
- If something is made of something else, then that something contains at least one of that something else