Opacity: The amount of light obscured by particulate pollution in the air; clear window glass has zero opacity, a brick wall is 100 percent opaque. Opacity is an indicator of changes in performance of particulate control systems.
👇 ស្វែងរកឯកសាររៀននិងការងារគ្រប់ប្រភេទនៅទីនេះ៖
👇 ស្វែងរកពាក្យផ្សេងទៀតនៅប្រអប់នេះ៖