Epidemiologists
(epidemiologist 的复数) n. 流行病学家
🗣️ 情景例句
Thanks ... for what?
谢什么？
Where did you go yesterday?
你昨天去了哪里？
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）。