预作用喷水灭火系统管线的充水时间不宜大于3分钟，每一报警阀控_爱下问搜题

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问题单项选择题

预作用喷水灭火系统管线的充水时间不宜大于3分钟，每一报警阀控制喷头数不宜超过（）个。

A、800

B、850

答案

参考答案：A

单项选择题

遮色瓷层厚度最佳应为

A．0.01～0.05mm

B．0.1～0.2mm

C．0.3～0.4mm

D．0.5～0.6mm

E．0.7～0.8mm

单项选择题

Had you come five minutes earlier, you（）the train to Birmingham. But now you missed it.

A.would catch

B.would have caught

C.could catch

D.should catch