premise1: A biker, wearing full protective gear including helmet, is jumping from a small hill in a brown lot.
premise2: Dirt biker number 52 making a high jump while riding his trail
premise3: A man on a motor cross bike jumping a dirt mound.
premise4: A dirt biker gets some air over a jump.
premise: A biker, wearing full protective gear including helmet, is jumping from a small hill in a brown lot. Dirt biker number 52 making a high jump while riding his trail A man on a motor cross bike jumping a dirt mound. A dirt biker gets some air over a jump.
hypothesis: Men doing martial arts.