Barrier

barrier method 柱式开采法 barrier reef n. 堤礁（珊瑚礁的一种）; 堡礁 barrier board barrier methods barrier boards barrier island 障壁岛；[海洋] 堰洲岛 barrier islands barrier reefs barrier to entry [经] 进入(市场)的壁垒 barrier rogue barrier rogues barrier troops 督战队 barrier cream barrier creams barrier ridge