混凝土垂直泵送管道不得直接装接在混凝土泵的输出口上,应在垂直管前端加装长度不小于() 发布时间:2017-08-27 19:26 │ 来源:www.tikuol.com 题型:单项选择题 问题: 混凝土垂直泵送管道不得直接装接在混凝土泵的输出口上,应在垂直管前端加装长度不小于()m的水平管,并在水平管近泵处加装逆止阀。A.25B.20C.15D.10
题型:单项选择题 Automatic identification systems(AIS)are required to().A.provide safety-related information automatically to shore stations,other vessels and aircraftB.receive safety-related information automatically from similarly equipped vesselsC.exchange safety-related information with shore-based facilitiesD.All of the above 查看答案