近来 ,在我们湖南境内的一些国道和省道的路边上 ,笔者常看到这样的牌子 :“加井水”、“加纯井水”、“加正宗井水”等 ,以招引来往过路车辆加水 ,满以为井水干净 ,殊不知发动机水箱加井水 ,是十分有害的。水可分为硬水与软水两种 ,当水存在着钙和镁等盐类时 ,水便有硬性 ,叫? Recently, on the roadsides of some of our national and provincial highways in Hunan Province, I often see such brands as “adding well water,” “adding pure water,” and “adding well-well water” Vehicles add water, thought it was well water, do not know the engine water tank plus well water, is very harmful. Water can be divided into two kinds of hard water and soft water, when there is water such as calcium and magnesium salts, the water has a hard, called?