Ethinylation
乙炔化
🗣️ 情景例句
All right, but I'm buying next time.
好吧，不过下回我付钱。
Opportunity only knocks once.
机不可失，时不再来。
I will have to choose presents for all the family soon, but I haven't chosen any yet!
我很快就要为每一位家庭成员选购礼物，但我至今还什么也没买！