A high school in the New York City suburbs has a high number of twins set to graduate this year. Among the 447 seniors at Plainview-Old Bethpage John F. Kennedy High School on Long Island are 15 sets of twins. Many of the students in the tight-knit group have known each other since kindergarten. Some even plan family vacations together. The students are all fraternal twins so none of them are identical. Most are heading to different colleges. Other schools in the country are also set to graduate large groups of twins, including one in California with 14 pairs.