Bivacancy
(在原子外壳中的)双空位
🗣️ 情景例句
How are you getting on with your studies?
你功课情况如何？
A guilty conscience is a self-accuser.
做贼心虚，良心自诛。
has spent his lifetime studying active volcanoes and deep caves in all parts of the world.
花了毕生的精力来研究世界各地的活火山和探洞。