题目: 为了防止离心压缩机在运行时发生喘振,设计时必须使压缩机有较宽的稳定工作区域,还可以采用正确防喘措施,以下措施中不正确的是( )。A.转动进口导叶及改变转速B.排气端节流调节C.用出口压力来自动控制回流阀开度D.防喘放空 答案: 参考答案:B
题型:选择题 ---Excuse me. Could you wake me up when my friend _______here?---Of course. But we still don’t know when your friend ______ here.A.comes;will comeB.comes;comesC.will come; comesD.will come; will come 查看答案