含有二氧化碳较多的水,pH(),呈()性,会腐蚀金属,同时会加速()对金属的腐蚀,是一种有害杂质。
民族英雄郑成功的家乡在哪里?() ["仙游","莆田","南安","绍武"]
平流雾形成的有利条件有:()。 ["晴夜","微风","层结稳定","空气湿度大","E.气地温差大","F.风速2-7/s"]
下列试剂中,()属混凝剂。 ["A、聚丙烯酰胺","B、硫酸亚铁","C、活化硅胶","D、海藻酸钠"]
唐代武德年间,伊斯兰教创始人穆罕默德的门徒大贤四人来中国传教,一贤传教广州,二贤传教扬州,三贤、四贤传教哪里?() ["厦门","漳州","泉州","福州"]
鸟类的羽毛分哪几种?