Complex sentence: When Bimbo opens Betty's garbage bag Betty Boop leaps out and kisses Bimbo, the cart then roles down the hill and turns into a home for Betty and Bimbo.
Split into simpler sentences: When Bimbo opens Betty's garbage bag, Betty Boop leaps out and kisses Bimbo. The cart then rolls down the hill and turns into a home for Betty and Bimbo.