3. avoid dropping things from that high. If necessary there should be material support to reduce the siangkrathop of things with construction area by may use rubber or carpet, etc.
3. Avoid throwing objects from height. If necessary, with material support to reduce the impact of substance to the construction area. You may also use a rubber mat or carpet and so on.
3. Avoid leaving things from a height. If necessary material should be supported to reduce the clanging of things with the construction area, the spread of Anyang or carpet, etc.