बिहार के मैदान की औसत ऊँचाई कितनी है ? - What is the average height of Bihar plain? - Bihar Ke Maidan Ki Average Unchai Kitni Hai ? Bihar Gk in hindi, Geographical Structure 66 Meter question answers in hindi pdf 76 Meter questions in hindi, Know About 55 Meter Bihar Gk online test Bihar Gk notes in hindi quiz book 96 Meter