sentence2: हालैका वर्षहरुमा हिउदको ठीक पहिले उत्तर भारतका धेरै भागहरूमा तुवाँलोले ढाकिने घटनाहरु बढ्दै गएको छ। २०१७ मा यो समस्या नाटकीय रूपले खराब भएको छ। ट्विटर प्रयोगकर्ता @gandabherunda द्वारा अपलोड गरिएको तलका फोटोहरूले अक्टोबरको अन्त्यमा तुवाँलो कति बाक्लो थियो भन्ने देखाउँछन्।
sentence1: There have been increasing instances of smog engulfing many parts of North India just before the winter in recent years. 2017, however, has seen the problem worsen dramatically. The photos below, uploaded by Twitter user @gandabherunda, illustrates how thick the smog was at the end of October.