问题
单项选择题
细砂及双层滤料过滤时，滤料层厚度和有效粒径之比应大于( )。
A．1250
B．1200
C．1000
D．800
答案
参考答案：C
解析：为保证过滤效果，《室外给水设计规范》(GB 50013—2006)第9.5.5条中规定了各种滤料的滤料层厚度和有效粒径之比(L/d10)的数值。
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细砂及双层滤料过滤时，滤料层厚度和有效粒径之比应大于( )。
A．1250
B．1200
C．1000
D．800
参考答案：C
解析：为保证过滤效果，《室外给水设计规范》(GB 50013—2006)第9.5.5条中规定了各种滤料的滤料层厚度和有效粒径之比(L/d10)的数值。
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