计算泵的有效功率时，系数K在离心泵中取（）。
A.0.6
B.0.8
C.1.0
D.1.2
参考答案：C
省局对全省性会议实行（）制度。
A.把关
B.审查
C.审批
D.审核
Tom, what did you do with my documents? I have never seen such a（）and disorder!
A.mass
B.mess
C.guess
D.bus
