context: How to get rid of snails in an aquarium
Avoid overfeeding.
Overfeeding can led to a snail population boom. Try underfeeding your aquarium inhabitants (only feeding enough for the fish to eat at each feeding) to see if that solves snail overpopulation.
****
next sentence for the context: Use a chemical to kill the snails. The most common, fish-safe chemical used to kill snails is copper sulfate.

context: How to change a car radiator
Take off the radiator cap.
Only do this when the engine is cool. This will release pressure on the cooling system and prevent vacuum lock when draining.
****
next sentence for the context: Squeeze the radiator hoses. If you feel a crunching sensation when you squeeze the hoses you probably have rust in the cooling system.

context: How to deal with bad medical news
Be positive, yet prepared.
If the doctor has called you to go over test results, stay calm. While there is a good chance the diagnosis will not be the best news, try to stay positive.
****
next sentence for the context: It's not good to worry prior to the news, as that will just cause stress and anxiety. Your initial feeling will be that of shock and disbelief.

context: How to hold a bowling ball
Insert your fingers into the ball.
If you're using the popular 3-hole bowling ball, place your dominant hand thumb in the larger bottom hole and your middle and ring fingers in the two adjacent holes at the top.
Use both hands to hold the ball.
****
next sentence for the context:
Rest the ball in your dominant hand, but use the support of your free hand to cradle the ball from underneath as you move towards the lane. This allows you to steady the ball and prevents you causing strain to your bowling hand.