concept dictionary

例句：

1. 1. The concept of space travel is fascinating to me.
   太空旅行的概念对我来说非常吸引人。
2. 2. The scientist proposed a new concept for solving the problem.
   科学家提出了一个解决该问题的全新概念。
3. 3. The concept of sustainability has gained significant attention in recent years.
   可持续性的概念近年来引起了广泛关注。