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。
Their humbler followers, such as partridges, have a like power of strong propulsion, but soon tire.
次于野鸭和鸽子的鸟,如鹧鸪,有相似的巨大推动力,但很快会疲劳。