(7) Hand held electric tools must be effectively grounded, unless it is an approved double insulated tool . Safe use of gas cylinder in high altitude hot work welding 7
Only the sky above Beijing in late autumn is wide and blue. After the left gate and the right gate of Chang’an on both sides of Tiananmen Gate have been
2.6 quality requirements: the allowable deviation of post cast strip width is ± 10mm. 1.4 key control points: falling distance of rammer, number and sequence of ramming blows Compaction spacing