来自刘士喜的问题
【greatchanges----inourcityinthepastthreeyears1tookplace2havetakenplace2havetakenplace3weretakenplace4havebeentakenplace急-----------理由】
greatchanges----inourcityinthepastthreeyears1tookplace2havetakenplace2havetakenplace
3weretakenplace4havebeentakenplace
急-----------
理由
