middlemann.中间人；经纪人middleadj.中等的；中间的；中期的n.中间vt.放在中间；把 ... 对折middle internodal tract中结间束Middle-fine sandstone中细砂岩middle-high elevation中高海拔middle-maturity group中熟组middle genicular artery膝中动脉middle- and old-age中老年Middle schools in towns城镇中学Middle-Upper Devonian中上泥盆统middle frequency source中频电源middle-pier cofferdam中墩围堰