Audra Buechele, center, sprays silly string June 5 while celebrating with 111 other members of the Karns City High School Class of 2008 after commencement ceremonies at the high school stadium. This year was bookended by two teacher strikes. Seneca Valley finalized a new labor contract in April after two years of negotiations and a strike, and South Butler, which is in nonbinding arbitration, went on an 18-day strike in October.