卫生许可证制度
高分子防水卷材单位面积质量测定时,试样应按卷材宽度方向裁取,相互间隔不超过()mm. ["100","250","500","750"]
拉线所受拉力大小和吊线形成的张力成()。 ["正比","反比","不变","无关"]
通信线路拉线的安全系数一般杆路为K=()。 ["1~1.5","1.5~1.8","1.8~2","2~2.5"]
对于高分子防水卷材厚度测量试样制备最外端的试件应距卷材边缘()mm. ["100±5","100±10","200±5","200±10"]
可控成本