chemistry and electricity meaning in English

化学与电学

At present , the distance of the pipelines running in the industry of oil refining , petrol - chemistry and electricity in china is around 500 , 000 kilometres . the majority of them last one or two decades , gradually resulting in the summit of accidents with various degrees of erosion and cracks
我国石油、化工等行业的在役油气长输管道总长约50万公里，其中大部分管道已使用10 ? 20年以上，出现不同程度的腐蚀、裂纹等缺陷，逐渐进入事故高发期。