Less than a third drink a glass a day, down from about half 25 years ago
                                
                                
                                    (Newser) -
                                    Fewer US teens are smoking, having sex, and doing drugs these days. Oh, and they're drinking less milk, too. Less than one-third of high school students drink a glass of milk a day, according to a large government survey released Thursday. About two decades ago, it was nearly half....