A.2△t
B.3△t
C.4△t
D.5△t
[单选题]A.2△tB.3△tC.4△tD.5△t
[单选题]A.2△tB.3△tC.4△tD.5△t
[单选题]A.2△tB.3△tC.4△tD.5△t
[单选题]A.(1),(2),(3)B.(1)C.(1),(3)D.(2),(3)
[单选题]A.(1),(2),(3)B.(1)C.(1),(3)D.(2),(3)
[单选题]A.50mmB.60mmC.70mmD.80mm
[单选题]A.①管道顺序号;②物料介质代号;⑥保温代号;⑦管道公称压力等级B.①装置(工段)编号;④公称直径;⑤管道等级;⑨管道材料类别C.③管道顺序号;④公称
[单选题]A.因电阻R未知,而无法求出B.3AC.2AD.-2A
[单选题]A.728.32kPaB.897.52kPaC.928.32kPaD.1147.52kPa