key concept的用法和樣例：
例句
- The cardinal concept is that of the Tao, the ineffable, eternal, creative reality that is the source and end of all things.
道的主要概念，是不可說，永恆，創造性的實體，是萬物的源頭和終結。 - The main concept underpinning this programme encompasses matching insights from both Slovenian and international instructors, and a wide range of teaching methods.
主要概念支撐這個方案包括匹配來自斯洛維尼亞和國際見解教員，以及廣泛的教學方法。
