单词	前形成层
释义	同前形成层--原始形成层
随便看	three-point support three-point suspension three-point suspension dynamometer three-point switch three point test three-point turn three-point-turn width three pole three pole angling three-pole capacitor three-pole circuit beaker three-pole circuit breaker three pole disconnector three-pole double-throw knife switch three-pole gang operated switch three-pole switch three-port connection valve three-port junction three-port networks three ports connection valve three position three-position control three position controller three-position controller three-position element