甲乙两球初速度相同,甲球与水平成α角斜上抛,乙球沿与水平成角的光滑斜面上滑,不计空气阻力,则它们能达到的最大高度H甲和H乙的关系是( )
南北美洲地形的相同点是
—Do you think I should get a good camera ?—Yes , of course ._______, you also need a good map and comfortable shoes.