测量出管道内流体的平均速度,再乘以管道截面积求取流体的体积流量,这类仪表是()。
A、直接式流量仪表
B、速度式流量仪表
C、质量式流量仪表
D、体积式流量仪表
参考答案:B
— What did the English teacher talk to you last Friday?
— She told me to ____ my lessons carefully before the exam. [ ]
A. look up
B. go over
C. look after
D. go on
建筑施工的伤亡事故主要发生在物体打击、高处坠落、机械伤害和( )五个类别中。
A.触电、火灾 B.坍塌、车辆伤害C.触电、坍塌 D.冒顶、车辆伤害