桥梁支座安装前,应将()和锚栓孔清理干净,做到无泥土、无浮砂、无积水、无冰雪及油污,并对支承垫石进行()。
参考答案:支承垫石;凿毛处理
—What a clean and bright classroom, isn’t it?
—Yes, it’s always clean and bright because it every day.
A.cleans
B.cleaned
C.is cleaned
D.was cleaned
选择综合防垢剂中各成分时,为凝聚水中胶体等杂质,当水中二氧化硅含量较高时,可以添加硫酸亚铁。()