कोसी नदी घाटी परियोजना निम्न में से किस वर्ष प्रारम्भ हुई थी ? - In which of the following year was the Kosi River Valley Project started? - Kosi Nadi Ghati Pariyojana Nimn Me Se Kis Year Prarambh Hui Thi ? Bihar Gk in hindi, Canals and Irrigation 1948 question answers in hindi pdf 1952 questions in hindi, Know About 1950 Bihar Gk online test Bihar Gk notes in hindi quiz book 1954