The photo taken with multiple exposure on May 21, 2018 shows a view of the Marzahner Bockwindmuehle, a wind mill built in 1993 as a replica of a 19th century mill in Berlin, capital of Germany. On Monday, more than 1,100 mills across Germany, historic ones and replicas, had their giant blades turned and grinders powered on to celebrate the 25th German Mills Day. (Xinhua/Shan Yuqi)