Elementary education
辅助 Assistant初等教育,小学教育
🧩 词语组成解析
🗣️ 情景例句
China is implementing a family planning policy.
中了在实施计划生育政策。
That's impossible.
那是不可能的。
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）。