सुरक्षात्मक ओजोन परत मुख्य रूप से पृथ्वी के वायुमंडल की किस परत में केंद्रित है?

The Dandi March, also known as the Salt Satyagraha, was led by which influential leader?

Which act formally granted independence to India, marking the end of British rule?

Who was the key figure in establishing the Indian National Congress?