A railway engineering corps documentary photo exhibition themed with "Immortal Military Spirit" is held at the Lanzhou Library in the city on August 1, to celebrate the 90th anniversary of the founding of the People's Liberation Army (PLA). Founded in July of 1948, the PLA railway engineering corps once made great contributions to railway construction across China and it was incorporated into the Ministry of Railways in December of 1982. [Photo/Gscn.com.cn]