Cavalries
(cavalry 的复数) n. 骑兵
🗣️ 情景例句
I'm afraid i have a complaint to make.
恐怕我要提点意见。
No problem.
没问题。
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）。