primary protective barrier是什么意思

网络释义

1)primary protective barrier,掷护墙2)fencing wall,护墙，围墙3)revetment,护岸墙;护墙;护坡4)barricade,防护墙,隔墙5)Dado,护墙板，墙裙6)parapet wall,护墙;矮墙;护栏