three rowadj.三行的threenum.三n.三；三个adj.三个的three tier structure三层结构three-row keyboard三行键盘three-square scale三棱尺three-state output[计] 三态输出three-shift system三班制three-phase bubble三相泡沫three-pen recorder三笔记录仪three major diseases三大疾病three ammeter method三安培计法three-stable state三稳态