A.
B.
C.
D.
E.
[单选题]A.2.146B.2.041C.2.112D.2.075
[单选题]A.2.146B.2.041C.2.112D.2.075
[单选题]A.y″+9y′=0B.y″-9y′=0C.y″+9y=0D.y″-9y=0
[单选题]A.y″+9y′=0B.y″-9y′=0C.y″+9y=0D.y″-9y=0
[单选题]A.0.0145~0.0155B.0.02~0.021C.0.022~0.023D.0.024~0.025
[多选题]A.B.C.机械送风量约9.1kg/s,室外自然补风量1.9kg/sD.机械送风量约9.6kg/s,室外自然补风量2.4kg/s