Title: वैकल्पिक

Text: A safety lamp is any of several types of lamp that provides illumination in coal mines and is designed to operate in air that may contain coal dust or gases, both of which are potentially flammable or explosive. Until the development of effective electric lamps in the early 1900s miners used flame lamps to provide illumination. प्रत्येक पराग्राफले परीक्षण हुनेछ।

Save test: यदि तपाईं यो टाइपिङ परीक्षणलाई साझा गर्न चाहानुहुन्छ भने यो प्रयोग गर्नुहोस् (केवल प्रमाणीकृत प्रयोगकर्ताहरूको लागि)।