门架的跨距和间距应按设计规定布置，但间距宜不小于（） ["0.8m","1.2m","1.5m","2.0m","0.5m"]
扣件拧紧力距应为（） ["40-65N·m","20-30N·m","30-40N·m","70-80N·m"]
什么是噪声？噪声污染有什么特点？（声音的合成）噪声的防治措施有哪些？
扣件式钢管支架高于（）时应设置水平剪刀撑 ["4.Om","5.Om","6.Om","7.Om"]
多排扣件式钢管模板支架，四周应设通长竖向剪刀撑，中间纵横方向每隔（）应设置一道竖向剪刀撑 ["A．4-5个立杆间距或5-7m","B．6-8个立杆间距或7-9m","C．8-10个立杆间距或8-10m","D．2—4个立杆间距或2~4m"]
电刺激坐骨神经-腓肠肌标本引起的骨骼肌收缩经历了哪些生理反应过程？
