the under-developed areas

• 欠发达地区

the under-developed areas的用法和样例：

例句

1. It is right to establish economic cooperation between developed and less developed areas.
   在发达地区和相对欠发达地区搞经济协作区，这是对的。
2. Therefore, we should research into the building of schoolmasters for the underdeveloped areas.
   因此，必须加强经济欠发达地区普通中学校长队伍建设研究。