Skolelevers drogvanor - 2006 B, 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，一项面向瑞典九年级学生的全国性药物使用习惯调查持续开展。自2004年起，同时还针对……二年级学生开展年度调查。