s. conforming to the same principles or course of action over time
a. 不变的
1. The weather in this region is unchanging throughout the year.
这个地区的天气在一年中保持不变。
2. She has an unchanging love for her family.
她对家人的爱始终如一。
3. The rules of the game are unchanging, making it easy to learn.
游戏的规则始终不变，使学习变得简单。