भूगर्भिक काल में गंगा का मैदान एक सागर था, उसका नाम है一 - In the geologic period, the Ganges plain was an ocean, its name is - BhuGarbhik Kaal Me Ganga Ka Maidan Ek Sagar Tha , Uska Naam Hai- Bihar Gk in hindi, Geographical Structure Arawali Sagar question answers in hindi pdf Georgia Sagar questions in hindi, Know About Tethis Sagar Bihar Gk online test Bihar Gk notes in hindi quiz book Arab Sagar