Pneumatization
n. [医](骨或其他组织中的)气腔形成
🗣️ 情景例句
How about a date with your grandfather?
和你爷爷约个会好吗？
Civility costs nothing.
礼貌不须什么代价。
They had to edge their way along this, sometimes wading across shallow streams, or swimming across deep pools.
他们不得不侧着身子往前走，有时过浅溪，有时游过深潭。