Unobtanium
n. 电影《阿凡达》中一种罕见的常温超导体，拥有奇特的磁场
🗣️ 情景例句
at all the great places in the city.
去城市所有的好地方看看。
Know something like the palm of one's hand.
熟知其事，了如指掌。
What languages did they speak?
他们讲什么语言？