निम्नलिखित में से किस शिक्षण पद्धति में मुख्य रूप से छात्र सक्रिय रूप से व्यावहारिक रूप से करके (learning by doing) सीखते हैं?

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?