Petscheckite
铌钽铁铀矿
🗣️ 情景例句
Thank you for your reassurance, Dr. Stewart.
谢谢你消除了我疑虑，Stewart大夫。
It's Monday today.
今天是星期一。
Could you explain exactly what you do?
您能确切的解释一下你做些什么吗？