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。
but belongs to the air, travelling it may be six thousand miles to and from its northern nesting home, feeding its flown young as it flies,
在空中十分自如,可以飞行6,000英里,可以飞往北方做窝的老家,再从老家飞回;一边飞一边喂养会飞的雏燕,甚至在顶风时也能在气流中滑翔,似乎气流在帮它前进。