triad

例句：

1. 1. The triad of elements in this formula is crucial for its effectiveness.
   这个公式中的三个元素对于它的有效性至关重要。
2. 2. The triad of skills required for success includes leadership, communication, and problem-solving.
   成功所需的技能包括领导力、沟通能力和解决问题的能力。
3. 3. The triad of emotions experienced during the test was anxiety, fear, and excitement.
   在考试期间经历的三种情感是焦虑、恐惧和兴奋。