Skolelevers drogvanor - 2011, gymnasiets år 2

Since 1971, a national drug habit survey has been conducted among Swedish ninth graders. From 2004, annual survey are also being conducted among students in the second year of...自1971年起，一项面向瑞典九年级学生的全国药物使用习惯调查持续开展至今。自2004年起，同步面向……二年级学生实施年度调查。