The exhausted man needed to have rest, he soon fell to what?
Options:
- relax
- sit down
- sleep
- his death
- closing eyes
Let's do it gradually: Exhausted means loss of all energy. Losing all energy causes sleep.... So the answer is sleep.

The work was pure math. It couldn't be what to practical applications?
Options:
- contaminated
- dirty
- smoothed
- corrupt
- applied
Let's do it gradually: Pure math is not applied everywhere. Work of pure math couldn't applied to a practical application.... So the answer is applied.

What do animals do when an enemy is approaching?
Options:
- feel pleasure
- procreate
- pass water
- listen to each other
- sing

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Let's do it gradually: When enemy is approaching animals warn the other animals about it. When other animals warn about something they listen to each other.... So the answer is listen to each other.