This topic investigates the development trend of modern education system. Development trend of modern education system: (1) Strengthen preschool education and attach importance to the connection with primary education; (2) Strengthen the popularization of compulsory education and extend the period of compulsory education; (3) General education and vocational education are developing in the direction of mutual penetration; (4) The types of higher education are increasingly diversified; (5) The boundary between academic education and non-academic education is gradually weakening; (6) The education system is conducive to international exchange; (7) Building a lifelong education system. Among them, lifelong education is an important symbol of modern education. Therefore, this question chooses C.