区段（区间）出清； 取消闭塞

relationship of clearing clearing of fault clearing of estate clearing of tracks clearing of accounts clearing of main lines clearing section of groove number of section form of section section of earthwork Fuchs lines of clearing balance of clearing clearing time of fault Fuchs' lines of clearing clearing of respiratory tract clearing of checks clearing of site probability of obstacle-clearing clearing of a fault clearing price of exchange clearing of bills cost of clearing