Ostwald's theory of indicator

例句：

1. 1.The Ostwald's theory of indicator is widely used in the field of environmental science.
   奥斯瓦尔德指标理论在环境科学领域得到了广泛应用。
2. 2. This research is based on Ostwald's theory of indicator, which has been proven to be effective in solving environmental problems.
   这项研究基于奥斯瓦尔德指标理论，已被证明在解决环境问题上是有效的。
3. 3. The Ostwald's theory of indicator provides a new perspective for understanding the relationship between human activities and environmental changes.
   奥斯瓦尔德指标理论为理解人类活动与环境变化之间的关系提供了新的视角。