invading army lays siege to city walls basically throwing themselves at it
move camera to top of wall where they see defending forces busily working away to defend, clearly winning. show enemy soldiers dissolve into ash and dust as they hit the wall. try to emphasis how one sided this fight is for the defenders. then play, in chinese of course, "He will win who, prepared himself, waits to take the enemy unprepared. " sun tzu.
as quote plays let scene dissolve into a home scene where a mother is helping/watching her son do schoolwork. its a scene where they are happy because they have only clean air in the house. have narrator continue speaking. "prepare yourself to win the war against pollution for your families health. call xxxxxxx or visit xxxxx.com and never be caught unprepared again.