Undulations
(undulation 的复数) n. 波动, 波状弯曲, 起伏\\n[医] 波动
🗣️ 情景例句
If you'd like to hear some new English songs, I suggest you download them from the web.
如果你想听一些新的英文歌，我建议你上网下载。
All things must come to an end.
天下无不散的筵席。
But which language is the most widely spoken in the world?
但是世界上哪种语言运用最广泛？