久久艹免费视频,久艹久艹,操逼视频二三区,伦理老熟女7777

Climb principle :to achieve a certain strength(10MPa) of the wall as a carrier,using its own hydraulic system and two climber of anti-falling down and up devices were to upgrade rail and support,to achieve frame body and the rail to climb mutually,to ensure the safety of climbing steadily; reuse the back-shift device to achieve the level of advance and retreat.Simple and flexible,the template positioning accuracy high to enhance the speed,the construction process without additional lfting equipment.