Effects of quality index, which are volcanic ash activity, loss on ignition, fineness and water demand ratio, on quality of fly ash are expatiated, the requests to quality of fly ash are put forward.

阐述了火山灰活性、烧失量、细度和需水量比等品质指标对粉煤灰质量的影响，对粉煤灰品质提出了要求。

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High population density, a poor ratio of available water to demand, and regional imbalances in available water supplies are serious challenges for China in managing its usable water supply.

FORBES: Quenching China's Thirst For Water