Skolelevers drogvanor - 1977, årskurs 9

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，一项全国性药物使用习惯调查便在瑞典九年级学生群体中开展。自2004年起，针对……二年级学生的年度调查也同步启动。