单词	重砂--黑砂
释义	黑砂 ; 重砂black sand黑砂；重砂black sand
随便看	negative potential energy negative practice negative precursory swing negative predictive value negative pregnant negative prescription negative pressure negative pressure breathing negative pressure grainage negative pressure isolation room negative pressure load negative pressure protection system negative pressure real casting negative pressure relief valve negative pressure slider negative pressure slider，nps negative pressure vacuum hot wall furnace negative pressure valve negative primaries negative--primary negative principal planes negative principal points negative profit negative program negative proposition