descentn.下降；下坡；家世；血统；侵袭；衰落；继承Descent to and Maintain下降至并保持…尺高度Descent Orbit Insertion下降轨道进入descentional ventilation下行通风descent iteration method下降迭代法Descent Propulsion System下降推进系统descent vaginae posterior阴道后壁脱垂descent of presenting part先露部下降descent-marking function下降尺度函数descent velocity of burden炉料下降速度descent iterative algorithm下降迭代算法