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。
As is so often pointed out, knowledge is a two-edged weapon which can be used equally for good or evil.
正像人们常常指出的,知识是一把双刃刀,可以用于造福,也可以用来为害。