Librations
(libration 的复数) n. 摆动, 天平动
🗣️ 情景例句
If you go camping, at night you'll hear all the nocturnal animals.
如果你去野营，晚上可以听到动物的夜歌。
How long will it take you to make it?
你要多久才能做好它？
Officials from Greenwich Observatory have the clock checked twice a day.
格林尼治天文台的官员们每天两次派人矫正此钟。