秦砖汉瓦E盘:https://www.wendangku.net/doc/bd8702457.html,/同是土木人:https://www.wendangku.net/doc/bd8702457.html,/
QQ:523874447
N/mm2
9*20+0.08*13/0.0101) 1.9*20+0.08*10/0.01)