OPENS AUGUST 21 Is it a carnival, casino, amusement park, international shopping pavilion, food haven or farm? All that and much more fun lies within “the CNE” grounds, a.k.a. the Canadian National Exhibition. Take a dizzying roller-coaster ride, view a daily parade, play midway games or challenge an operator to guess your age or weight; pet and feed the horses or brave the haunted house. Enjoy free concerts, hypnotist acts and a nightly light show, too, and see why “The Ex” has been around for more than 130 years. Exhibition Place, $11 to $15; call 416-393-6300 for details.