If you had not drunk water from that well

your teeth would go bad.

If you ate sweets all the time

you might hit somebody's head.

If you don't use a mosquito net

you may fall off.

If you don't keep food in the fridge

you may catch malaria.

If you cycle with things in your hand

it will go bad in hot weather.

If you wave the stick in the air

you wouldn't have fallen in.