短語(yǔ)詞組短語(yǔ)down -turn hemming device 曏下卷邊器step -down turn ratio 降壓匝比economic downturn 經(jīng)濟(jì)低迷；經(jīng)濟(jì)不景氣；經(jīng)濟(jì)滑坡 返回 down-turn