three plyadj.三层的(三股的；三夹板)threenum.三n.三；三个adj.三个的three-flanged nail三刃钉,三叶钉Three Gorges granite三峡花岗岩three-phase system三相制,三相系three-point method三点法Three Gorges writing三峡书写three-field system三区制three-level scheme三层格式three major controls三大控制Three Gorges cascade三峡梯级three-necked flask三颈烧瓶