Aplanatism
[医] 消球[面]差
🗣️ 情景例句
Thanks for hearing me out. And ...
谢谢你听我的意见， 而且……
Buck up, Billy, Enjoy yourself.
振作起来，比利，快快活活地过日子。
and a period (which is the time it takes a wave crest to travel one wave length).
和周期（浪峰走过一个波长所需的时间）。