单词	workable seam
释义	workable seam 可采煤层
随便看	approach locking track circuit approach lock lamp approach management approach march approach march formation approach marker beacon approach-marker-beacon transmitter Approach measurement approach medium aspect approach-medium signal approachment approach method approach middle life approach motivation approach motive approach nature approach navigation approach nearby approach noise approach noiselessly approach nose approach object approach obstruction signal approach of approach of analysis of classes