CHICAGO (Reuters) - One in five U.S. teenagers say they have engaged in oral sex, an activity that some adolescents view as not sex at all and certainly less risky than intercourse, a report released Monday said. The survey of 580 children with a mean age of 14-1/2 found 20 percent said they had engaged in oral sex, compared to 14 percent who said they had engaged in sexual intercourse. In addition, one-third of the multi-ethnic 9th graders surveyed said they intended to have oral sex within the next six months and nearly one-fourth planned to have intercourse during the...