火药是由硫 、 碳和硝酸钾组成.Gunpowder is composed of sulfur, carbon, and potassium nitrate.氨对硝酸钾的选择分离结晶效果较好.And ammonia had effective selectivity for the separation of potassium nitrate.用氯化钾与硝酸铵为原料,采用复分解法生产农用硝酸钾与氯化铵.Agricultural pot...
乡村风光在微微开朗的天幕中暗淡地展露出来.The country expanded darkly defined underneath the moving curtain.他是个生气勃勃和思想非常开朗的人.He was a man of extraordinary vigour and liberality of mind.别为他担心; 他是个快活开朗的人.Don't worry about him; he is a che...