短語(yǔ)詞組短語(yǔ)canal river system 運(yùn)河水系canal transport system 漕運(yùn)制度canal distribution system 渠道分布系統(tǒng)North Canal River System 北運(yùn)河水系canal -system water use efficiency 渠系水利用系數(shù)open canal system 根部開(kāi)放structures for canal system 渠系建筑物canal safe transit system 運(yùn)河安全通航系統(tǒng)canal system density 渠系密度 返回 canal system