Based on the climatic data and other statistics of climatic data of 54 meteorological stations from 1956 to 2005 in Liangning Province,the annual and seasonal l
The root causes of subprime crisis are analyzed based on the introduction of the definition and features of subprime mortgage loans:firstly,a loose financial su
Based on the summarization of the status quo of the research both at home and abroad,the changing trend of the production of the main grain crops,covering the p