That would be Logos
Ethos is credibility of the person
Pathos appeals to emotion <span />
Since this is an open question with no choices, I am answering with what I think will best fill in the blank. Note: I do not know exactly what answer they are looking for.
The best answer is: REM
REM is the stage of sleep where dreaming occurs. REM stands for Rapid Eye Movement. Exactly as the title says, REM sleep is characterized by fast back and forth movement of the eyes.
Answer:
the first orginisms lived together to survive.
Explanation:
Simple and direct, kind of like it sounds. Short and to the point.
Hope this helped!