The ocean is a natural extension of land areas through river basins. In marine development activities, production links such as marine fishing, maritime transportation, marine mineral development, and mariculture are jointly completed in the sea areas and watersheds; while the production links such as sea salt industry and seawater utilization are Completely completed on land. In addition, while the development of modern science and technology promotes the advancement of marine technology and the development of the marine industry, the development of marine high-tech and the emergence of new products have also promoted the advancement of land-based science and technology and the development of related industries Sea and land products have developed interactively through this technological extension. What does this text mean? ['Dependence of the marine economy on the spatial distribution of the basin economy.', 'The development of modern technology has promoted the progress of the sea and land economy.', 'Marine economy and river basin economy are industrially intertwined.', 'The development of modern technology has promoted the convergence of sea and land economies.']