three plyadj.三层的(三股的；三夹板)threenum.三n.三；三个adj.三个的three-axis control三轴坐标控制three pulses control三冲量控制three-hinged frame三铰刚架Three-step heating三段式梯度加热three-high pierdng三辊穿孔three-side erosion三面侵蚀three-stranded DNA三链DNA, 三股DNAthree-ram specimen三冲试样three-position key三位(置)电键, 三触点电键Three wave equations三种波动方程