जेरोम ब्रूनर की संप्रत्यय सम्प्राप्ति (concept attainment) की विधि को निम्नलिखित में से किस लेखक द्वारा शिक्षण के एक औपचारिक 'संप्रत्यय सम्प्राप्ति मॉडल' का रूप दिया गया 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?