2. try not to drill in the area, there is less water because water cause erosion because that hole drilled will be opening for blower cutting up with water up to make the not-quite-taek or collapsing strength in hole, making a hole. The position of the hole punch and depth, it'll update the level of the job by the survey data, it will be used in a design by drilling to drill a 9 m provision for drilling holes drill 1 m sub is the direct use of drill head approximately 4 inches of penetration rate 18-30 meters per hour.
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