Chemene
季铵化合物
🗣️ 情景例句
Philip, do you have the key to the trunk?
Philip衣箱的钥匙在你那吗？
Practice is better than precept.
身教胜于言教。
Yes, please. This is Bill here. Is that Mrs Read?
是的，劳驾了。我是比尔。你是里德夫人吗？