A certain province has carried out the reform of the new college entrance examination  The subjects of the examination are set according to the mode of 3-3-1-2  3 is the unified national college entrance examination of Chinese, mathematics and foreign languages  1 is chosen by candidates in one of the two subjects of physics and history, and 2 is chosen by candidates in politics, geography, chemistry and biology
Most of the students who chose chemistry in a certain school chose physics, and those who chose politics chose history
Some students chose chemistry but not politics.