a lot(/world) of difference; as far apart as heaven and earth; be vastly different; make all the difference in the world; poles (/worlds) apart ❍ 欧阳反正是跑不掉了，可这一出一进对我是～啊！(宗福先《于无声处》45) After all Ouyang can’t escape. But to let him go or have him arrested makes a lot of difference to me. ❍ 它的军队和红军比较起来真有～。(《毛泽东选集》173) There is a world of difference between the Kuomintang army and the Red Army.
天壤之别
as far apart as heaven and earth;worlds or poles apart;world of difference
天壤之别tiān rǎnɡ zhī bié
天壤：天上和地下。比喻差别非常之大。worlds apart, vast difference, make all the difference in the world, a whale of a difference