Polyformaldehyde
聚甲醛
🗣️ 情景例句
Littering is a serious offense in some countries.
乱扔垃圾在某些国家是严重的违法。
So many countries, so many customs.
一个国家有一个国家的风俗。
Thanks, Bob. I won't.
谢谢，鲍勃，我不会的。