spend time on sth
spend time (in) doing sth我现在有一道题：Most teenagers spend their spare time___computer games.A.playB.playingC.to playD.on playingB我还想问一道：Are the children going___a holiday trip to London?A.aboutB.withC.toD.onC为什么不选D呢？不好意思打错了 应该选D go on a trip旅行