【建筑】在地洞或井内

grinding slim boreholes in nozzles

removing from the boreholes

plug with inflatable sleeve for the sealing of boreholes or wells

plug with elastic cup or skirt for the sealing of boreholes or wells

rotary type drive, pneumatically drive used in boreholes

appraisal drilling (drilling for enlarging boreholes)

packing of boreholes (packing of wells)

in boreholes fishing