Etfe
[医][=ethylene-tetrafluoro-ethylene]乙烯四氟乙烯
🗣️ 情景例句
This has been a hard course for me.
这门课对于我来说很难。
A faithful friend is hard to find.
益友难得。
Merry Christmas and best wishes for the New Year!
圣诞快乐，并致以新年的良好祝愿！