Polyketone
聚酮
🗣️ 情景例句
When will this time draft fall due?
期票什么时候到期？
Who is she?
她是谁？
I'm very sorry. Usually I'm very careful. I have never lost a book before. It won't happen again.
“很对不起。通常我是非常小心的。我以前从来没有丢过书。这样的事不会再发生了。”