To take warning or learn a lesson from what one sees; to be admonished by the sight of something.
看到那片被过度开发而荒芜的土地，真让人触目儆心，提醒我们保护环境的重要性。
Seeing that piece of land barren due to over-development was a truly admonishing sight, reminding us of the importance of environmental protection.
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