threefoleadj.三倍；增加二倍；三重的；三方面的；三次adv.三倍；增加二倍；三重地；三方面的；三次threenum.三n.三；三个adj.三个的three-piece pattern三开模three-tiered system三审终审制Three current control三电流环控制three-phase diagram三相图three state of matter[电] 物质三态three-axis tumtable三轴转台three-year sentence三年徒刑three-dimension use立体利用three types of talent三才three dimension model三维模型