Sure, it can be done, but it is much easier to juggle when one is standing on solid ground. 但是站在坚实地面变戏法就很容易，也是可行的。
After having experienced the difficult solid ground season opening, Feidler has found the condition gradually, he has won the Olympic Games doubles champion and the US Tennis Open. 在经历了艰难的硬地赛季的开局后，费德勒逐渐找回了状态，他赢得了奥运会双打冠军和美国网球公开赛。
