Ecos
abbr. 嵌入式可配置操作系统（Embedded Configurable Operating System）；扩展式通信操作系统（Extended Communication Operating System）
🗣️ 情景例句
The course I took was above me.
我上的这门课太难了。
Who will accompany you to the airport?
谁将陪你去机场？
Someone is ringing the bell.
有人在按门铃。