Incavo
凹刻的雕刻物
🗣️ 情景例句
I'm heading off for bed
我先去睡觉了
Experience is a school from which one can never graduate.
经验无止境。
Even more processes are never patented at all but kept as secret processes.
更多的工艺过程根本就不会取得专利权，而是作为秘方保存着。