方法2004年5月至6月，选取北京西城5所、河南新乡市3所中学的初中和高中学生461名，采取中学生危险行为问卷调查。
Methods During May and June , 2004 , a questionnaire about health risk behaviors was used in 461 secondary school students in Beijing and Xinxiang of Henan Province .
西城所