कौन सी मुख्य गैस प्राकृतिक गैस और बायो-गैस दोनों में प्रचुर मात्रा में मौजूद होती है?

The 'Drain of Wealth' theory was propounded by which Indian nationalist leader?

Which event is considered the turning point in Mahatma Gandhi's leadership in the Indian independence movement?

Which African leader is known for his non-violent opposition to colonial rule?