free jumper自由跳投；
free：能随自己意愿的；随心所欲的；不受限制的；
jumper：n.(毛或棉的)针织套衫；跳跃者；跳跃动物；跳虫
相关介绍
He had no shirt on under his thin jumper
他在薄套头衫里面没有穿衬衣。
He is a terrific athlete and a brilliant jumper
他是个出色的运动员，弹跳力非常好。
Her horse was a show jumper whom the family rescued from the knacker's yard.
她的马擅长跨越障碍，是家人从废马屠宰场挽救回来的。
