Boys reveal sex practices.
D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D020407:Internet; D008297:Male; D000297:Psychology, Adolescent / Q000706:statistics & numerical data; D012307:Risk Factors; D012736:Sex Education; D012725:Sexual Behavior / Q000523:psychology* / Q000706:statistics & numerical data; D012749:Sexually Transmitted Diseases / Q000209:etiology / Q000635:transmission; D011795:Surveys and Questionnaires