Nitrocalcite
钙硝石
🗣️ 情景例句
I want to send this letter to China, by air mail.
我想把这封信航空邮到中国。
He gets more professional satisfaction from teaching.
从事教育职业，他更感受到职业上的满足。
Please make sure I get an invitation.
请记住寄张请帖给我哦。