input question: To clean a laptop screen effectively.

output answer: Use a tissue paper to wipe the laptop screen.

input question: How to seal a small crack in plastic?

output answer: Light a candle and use the wax to fill the small gash, then use a blade to remove any excess wax

input question: To get my milk to last, while I am on vacation.

output answer:
Freeze half a jug of milk and it will be fine if you let it melt when you get back.