湄公河

例句：

1. 1. The Mekong River is the longest river in Southeast Asia.
   湄公河是东南亚最长的河流。
2. 2. The Mekong River flows through several countries and supports a rich ecosystem.
   湄公河流经多个国家，支持着丰富的生态系统。
3. 3. The Mekong River is a source of hydropower for many Asian countries.
   湄公河是许多亚洲国家的水力发电来源。