In 2003. The reason why the college entrance examination in Tianjin in 2003 was so difficult was to prevent the normal test paper of the college entrance examination from leaking, so the mathematics test paper of the college entrance examination was taken as a backup test paper, and some problems in the test paper became the reference for the purpose of the later mathematics competition. When the college entrance examination papers are leaked, lost or damaged locally, it is still complicated to enable backup papers and apply for backup papers.