निम्नलिखित में से कौन-सा एक गैर-प्रक्षेपित (नॉन-प्रोजेक्टेड) शिक्षण सहायक सामग्री का उदाहरण है?

Prolonged occupational exposure to excessive noise from heavy machinery without hearing protection causes noise-induced hearing loss. Excess noise is categorized as a:

Long-term exposure to indoor air pollutants, such as smoke from burning biomass fuels, significantly increases the risk of developing chronic respiratory conditions like: