17)a rock band provided the for johns graduation party.(entetain) 18) all shops in my area have major sales twice .(year) 19)the most violent voicanic in the united states was that of mount st. helens in 1980. (erupt) 20) the battle of britain is a historical event of great for the british people.(significal) 21)you need to get from your supervisor. (permit) 22)the fire was thought to have been caused by a gas (explode)