Students worldwide compete at international robotics event in Washington (3)

Students prepare their robots during a competition of First Global Challenge 2017, in Washington D.C., the United States, on July 17, 2017. Students from more than 100 countries and regions across the world with the common goal of increasing their knowledge of science, technology, engineering and mathematics, attended the international robotics event in Washington. (Xinhua/Ting Shen)