Diolefins
二烯属; 二烯属烃
🗣️ 情景例句
Excuse me, officer.
对不起 警官。
We have a toll-free number for customers to call.
我们对顾客提供免费服务电话。
but would you mind coming with me to the station?'
但请您跟我到警察局去一趟好吗？”