法律效力的概念对于理解法律的本质至关重要。
The concept of legal validity is crucial for understanding the nature of law.
我作品的短暂性是对生命本身的反映。
The artist deals with what cannot be said in words.
天然气开采的创新是满足世界日益增长的能源需求同时减少环境影响的关键。