F region
【气象学】F区,F(电离)层(＝F layer)
🧩 词语组成解析
🗣️ 情景例句
At what time?
几点？
You haven't been around much lately,have you?
你近来不大出来走动了，是吧？
You can enlarge your knowledge and learn some English at the same time.
你可以扩大你的知识面，同时又学习了英语。