内部电话

例句：

1. 1.The company has offices in several countries.
   这家公司在几个国家设有办事处。
2. 2. The book is about the history of China's internal development.
   这本书是关于中国内部发展的历史的。
3. 3.The team decided to work on the project internally before sharing it with the public.
   团队决定先在内部进行这个项目的工作，然后再与公众分享。