अत्यधिक प्रदूषण के कारण भारत की निम्नलिखित में से किस नदी को अक्सर 'खुली नाली' कहा जाता 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?