相关jumperyoucanjumponly的文学知识

问题详情：Evenifyouareagoodhigh-jumper,youcanjumponlyaboutsevenfeetofftheground.Youcannotjumpanyhigherbecausetheearthpullsyouhard.Thepulloftheearthiscalledgravity.Youcaneasilyfindoutthepulloftheearth.If...