bottomn.底部；底端adj.底部的v.触底；打(基础)bottomdumpn.车底卸载bottom box底箱bottom row底端行bottom gas积聚在低洼处的爆炸性气体bottom cap底盖bottom jib截盘bottom bed台面bottombars底杆bottom tap平底丝锥,下除渣口bottom man井底把钓工