निम्नलिखित में से कौन सी प्रयोगशाला/शोधन प्रक्रिया ऐसा जल प्रदान करती है जो व्यावहारिक रूप से सभी घुलनशील रासायनिक, जैविक और गैर-वाष्पशील अशुद्धियों से मुक्त होता है?

Which Indian independence movement leader was primarily known for his philosophy and practice of non-violent civil disobedience?

Who gave the call for 'Do or Die' during the Quit India Movement in 1942?

Which of the following revolutionary pairs were imprisoned together in Cellular Jail and faced harsh conditions, contributing significantly to the Indian independence movement?