前前后后算法
forward-backward algorithm
新轨道梁梁型
new-prototype guideway girder
阴道前后壁修补术
Vaginal anterior and posterior wall repair
赤道轨道卫星
satellite equatorial orbit
磁悬浮轨道梁
magnetic levitation railway girder
magnetic suspension track beam
灌注桩轨道梁基础
track beam foundation of cast-in- situ concrete pile