The shortage of water resources has always been a long-term, trending problem that China faces in the process of population growth, urbanization and industrialization, and has become a major bottleneck restricting China's economic development. Experts believe that seawater desalination is the most economical in coastal and coastal areas. The most practical and flexible water crisis solution. With the advancement of technology, the cost of seawater desalination will gradually decrease, and eventually it will reach the level of competition with urban tap water whose cost is gradually rising, thus being promoted on a large scale. The main emphasis of this passage is:. ['The necessity and feasibility of desalination.', 'Economics and practicality of desalination.', "Water crisis restricting China's economic development.", 'Effective measures to address the water crisis in coastal areas.']