Three young teachers, Ms. Cai, Ms. Zhu, and Ms. Sun are newly recruited in a school. Each of them teaches two subjects in six subjects: biology, physics, English, politics, history, and mathematics. Three of them have the following relationship: : (1) physics teacher and political teacher are neighbors; (2) teacher Cai is the youngest among the three; (3) teacher Sun, biology teacher and political teacher often come home from school together; (4) biology teacher ratio The math teacher is older; (5) On weekends, the English teacher, the math teacher and the teacher Cai often play volleyball together. According to the above conditions, Teacher Zhu can be introduced:. ['History and biology.', 'Physics and Mathematics.', 'English and biology.', 'Politics and mathematics.']