Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Former Asian junior champion Ma Yuqin set a new Asian record of 49.81 seconds, ranking her first of the world 400 metres top list in 1993. Zhang Hengyun, only 19, clocked 51.25 seconds to break the area junior record.