If legs drift toward bottom, as momentum slows, don't fight it.
如果腿向底部漂移，作为动力减缓，不要打它。
2
The vertical and parallel relations of the trench with drill drift are summarized by the bottom structure disposal design on inclined orebody footwall.
For median and low-rise reinforced concrete frame, the structures are dominated by shear deformation, which leads to the story drift of the bottom story large while the upper story small.