filtermask过滤式防毒面具filtern.过滤器；滤色镜；滤光器v.过滤；渗透filtered through the sand用沙过滤的filter input stream class过滤器输入流类filter-tipped cigarette过滤嘴香烟filter paper dust counter滤纸测尘计filter-tipped cigarettes(带有)过滤咀(的)香烟filtered bacterial culture过滤了的细菌培养液Filter in frequency domain频率域滤波filter theory of attention注意过滤论filter washing water inlet清洗液入口filter paper chromatograph纸色谱(法)