When I have a sponge, but am unsure of where to use it, where should I use it?
Options:
- wet surface
- clean dishes
- collect water
- hold water
- wet surface
Let's do it gradually: At wet surface, a sponge can be used. When I have a sponge but am unsure of where to use it then I should use it at a wet surface.... So the answer is wet surface.

What will always happen after taking phone call?
Options:
- communication
- regret
- decisions
- food
- car accident
Let's do it gradually: Phone call is a way to communicate. After taking phone call, communication takes place.... So the answer is communication.

The work was pure math. It couldn't be what to practical applications?
Options:
- contaminated
- dirty
- smoothed
- corrupt
- applied

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: Pure math is not applied everywhere. Work of pure math couldn't applied to a practical application.... So the answer is applied.