Polyanhydrides
[化] 聚酐类
🗣️ 情景例句
Is smoking allowed on the train?
火车上允许吸烟吗？
It's a beautiful country with many large rivers.
这个国家很美，它有很多大河。
How ever you may work hard, the boss will not be fully satisfied.
无论你有多努力，老板总不会完全满意。