सर्दियों के अंत और वसंत की शुरुआत में किस क्षेत्र में समतापमंडलीय ओजोन की भारी कमी को आमतौर पर 'ओजोन छिद्र' के रूप में जाना जाता है?

The International Day for the Preservation of the Ozone Layer is observed globally on which date?

Read the statements marked as Assertion (A) and Reason (R) and choose the correct option: Assertion (A): Delhi often reports extremely high Air Quality Index (AQI) values during winters. Reason (R): Its geographical position and landlocked nature restrict air movement, causing inversion and trapping pollutants.