开启三级模式环流气体流量72Nm3/h,真空槽内残余压力为2700pa时,环流速度()t/min。
A.73.9
B.113
C.95.4
D.125.7
参考答案:C
The final tests are coming, and the students _______ hard for them these days.
A.study
B.will study
C.are studying
D.studied
依据《环境噪声污染防治法》,在城市市区噪声敏感建筑物集中区域内,可以进行产生环境噪声污染的建筑施工作业的时间段是( )。
A.6:00~22:00 B.7:00~19:00C.8:00~19:00 D.8:00~20:00