downsn.丘陵名词down的复数形式.downadv.向下prep.沿着 ... 而下adj.向下的；消沉的；无礼的n.绒毛；汗毛v.击倒；打败；吞下；被抑制downandupadj.上下来回的(往复的；双动的)down vest羽绒背心down tank下流槽downeomer降液管down tilt翻平downpipes水落管down lead引下线down turn经济下降down tuben.车架下舌downcomern.泄水管(下导管)