यूरिया उर्वरक मुख्य रूप से पौधों को कौन सा पोषक तत्व प्रदान करता 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?