Zedeflon
四氟乙烯均聚物
🗣️ 情景例句
Is it too early to call Mr. Carlson?
现在打电话给Carlson先生会不会太早了？
I only had five dollars.
我只剩五美元。
It was very old and precious even then.
却使在当时，它也属历史悠久的珍奇之物。