निम्नलिखित में से कौन-सा मुख्य स्रोत/वाहक है जो महासागरों में घुले हुए लवणों को लाता है, जिससे महासागरीय लवणता में महत्वपूर्ण योगदान होता 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?