Polymethylene derivatives
[建] 聚甲烯衍生物
🧩 词语组成解析
n. [化]聚亚甲基
派生物
🗣️ 情景例句
and I'm running for the open seat on the school board.
我正在竞选联合校董会的席次。
I couldn't keep the appointment because I was sick.
我不能赴约因为我病了。
I've live here for twenty years.
我在这里住了20年了。