दुनिया का दूसरा सबसे अधिक आबादी वाला शहर कौन-सा है ? - Which is the second most populous city in the world? - Duniya Ka Doosra Sabse Adhik Aabadi Wala Shahar Kaun - Saa Hai ? Delhi Gk in hindi, General Studies Delhi question answers in hindi pdf Beijing questions in hindi, Know About Tokyo Delhi Gk online test Delhi Gk notes in hindi quiz book London