input question: To stop a burning sensation in your mouth due to eating spicy food,

output answer: put sugar inside your mouth instead of using water.

input question: How to remove scratch from the glass?

output answer: Wash off the glass using a clean cloth, making sure the glass is clear of all debris. Allow the glass to dry before attempting to fix the scratch. Hold a clean, lint-free cloth under a faucet of lukewarm water. Squeeze the cloth until no more excess moisture drips from it. Squeeze the tube until a pellet size of toothpaste comes out. Place the cloth and the drop of toothpaste on the scratched area. Move the cloth in small, circular motions for 30 seconds. Check the area to see how it looks. You may need several applications of toothpaste in order to minimize the scratch. Repeat the steps, applying a drop of toothpaste to the towel and wiping it on the scratch in a circular motion for 30 seconds. Get a fresh, clean cloth and wet it under the faucet. Squeeze out the excess moisture again, then take the damp cloth and pass it once over the glass. This makes the glass shine.

input question: To make it easier to paint a board,

output answer:
make the board smooth first by sanding it down with a fine grit sandpaper.