Polyfluocarbon
[化] 多氟烃
🗣️ 情景例句
worrying about him.
为他操心。
I've got a slight pain in my teeth.
我的牙有点痛。
Jim, could you help me, please? I want to get some books.
吉姆，你能帮我一下吗？我想拿些书。