Marken
软炭质页岩
🗣️ 情景例句
Time moved at a snail's pace before the holiday.
假期之前时间过得非常缓慢。
Scum of society.
社会败类。
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。