GL型三通阀的阶段缓解作用是通过（）来实现的。
A.作用部
B.递动部
C.旁通部
D.紧急部
参考答案：C
__________是学校中物质文化、制度文化、精神文化的统一体。
Which of the following describes the BEST use of historical records from previous projects ？（）
A．Estimating, life cycle costing and project planning
B．Risk management, estimating and creating lessons learned
C．Project management planning, estimating and creating a status report
D．Estimating, risk management and project planning
