sentence: A person mows the lawn while a dog and a person play catch with a ball on the same lawn at the same time. sentence:   A lawnmower begins mowing a small grass covered lawn while a dog walks around the perimeter. sentence:   The dog has a ball in its mouth, drops it in front of the lawn mower and a person off of the screen throws the ball to the dog, who runs after it. sentence:   The person continues mowing the lawn as the dog catches a thrown ball one more time and then drops it again in front of the lawn mower.