Sun (center) instructs her apprentices in welding skills in Nanjing on May 24, 2017. While pursuing advanced studies with France's Alstom, the other trainees didn't pay her much attention until she managed to weld an aluminum alloyed coachwork with a space of just 2 to 3 millimeters. Following this she was respectfully called "Madam Sun" by the crew at Alstom. [Photo provided to chinadaily.com.cn]