配制混凝土用砂的要求应尽量采用()的砂。 ["空隙率较大、总表面积小","总表面积大、空隙率较小","孔隙率和总表面积均较小","总表面积和空隙率均较大"]
通过学习《胜出天神赞》,你自己有哪些收获?倘若你周围有人不明白这些道理,你将会如何引导他们?
正常条件下,重油催化干气中氢气甲烷比应为() ["1:2","1:1","2:1","3:1"]
货叉的垂直段受()。 ["压缩力","弯曲力","扭转力","拉伸力","剪切力"]
正常操作条件下,外取热器水汽循环比应控制在() [">5",">10",">15",">20"]
考上公务员如何与人沟通,如何开展工作?