With a little help from this carbonic acid, moving water forms most of the world's limestone caves.
在这种碳酸的帮助下，流动的水创造了世界上大部分的石灰岩洞穴。
2
Also, in surface water, there is a weak acid, carbonic acid, not sulfuric acid, but carbonic acid that helps dissolve the rock.
另外，在地表水中存在一种弱酸，它是碳酸，而不是硫酸，而且是能帮助溶解岩石的碳酸。
3
Should the carbon dioxide mix with water underground and form carbonic acid, they say, it could leach poisonous materials from rock deep underground that could then seep out.