निम्नलिखित द्वितीयक (secondary) बैटरियों में से किस प्रकार को आमतौर पर सबसे अधिक बार शारीरिक रखरखाव की आवश्यकता होती है, जैसे कि इलेक्ट्रोलाइट स्तर को टॉप-अप करना?

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?