clearancen.清除；清理；清仓甩卖；间隙；许可证；结关；通关clearance permit出港证书,红单clearance sector[航空、航海]偏 航指示区clearance notice出港通知书clearance leakage间隙漏泄clearance drawing余隙指示图clearance of span桥跨限界clearance inwards结关入口clearance account结算帐户clearance surface留隙面clearance failure漏排,排雷不达标