Fluctuations
n. 起伏现象；变动；波动（fluctuation的复数）
🗣️ 情景例句
You must develop the muscles of your speech organs to produce unfamiliar sounds.
所以你必须训练和发展你的发音器官（声带、舌、口、鼻腔等）的肌肉，以便发出陌生的（另外一种语言）声音。
There is no longer any communication between them.
他们之间好久不说话了。
He glared at Bill, ready to teach him a lesson.
他怒视着比尔，准备教训他一顿。