在研究方法上，采用定性分析和定量分析相结合、纵向与横向、运输需求与供给对比分析、历史分析和结构分析的方法，实现了理论联系实际。
I apply many methods of analysis into practice , such as , qualitative and quantitative analysis , the contrast of the demand and supply of transportation , historical analysis and structure analysis .
横向运输