Standardized structure design of tetrad-ecoagricultural pattern in North China Patterns and programming for ecoagricultural divisions in Jiansu Province The Prospect of Eco-agricultural Development in China in the Current Movement of the World Sustainable Agriculture Ecoagricultural landscape for biodiversity conservation andecological service maintenance The main patterns of ecological agriculture in China and the ecology principles of their sustainable development Structure Models and Economic Benefits of Representative Ecological Households