Kettnerite
氟碳酸盐铋钙石
🗣️ 情景例句
I must prepare my lessons.
我必须准备工课。
Experience keeps a dear school,but fools learn in no other.
经验学校学费高，愚人旁处学不到。
We could visit the town of Aswan.
我们可以游览阿斯旺城。