एल.एच. मॉर्गन ने अपनी पुस्तक 'एंशिएंट सोसाइटी' में मानव समाज के विकासात्मक अनुक्रम को किन तीन मुख्य चरणों के माध्यम से प्रतिपादित किया था?

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?