Duan Cunrui (C) recommends old books to a customer at his old book store in Hohhot, capital of north China's Inner Mongolia Autonomous Region, April 19, 2018. Duan Cunrui, 70 years old, has run the bookstore in Hohhot for over 30 years, where he gathers about 100,000 old books. For him, books are one of the necessities in life and old books have their values to be collected. (Xinhua/Lian Zhen)