Kids are saying no to plastic across the Twin Cities after a cafeteria sit-in by grade schoolers prompted a school board decision to switch from disposable lunch trays and cups in favor of washable dishes. Mounds View school officials say they will spend at least $145,000 to equip eight grade schools with dishwashers and related equipment _ three schools next year and five the year after that. Students at Bel Air started the movement after hearing their teacher talk about the need to recycle and attending Earth Day festivities. They passed around a petition, which prompted school officials to call in a plastics representative to preach the benefits of plastic. That made them decide to stage a cafeteria sit-in. When they refused to return to class, they were suspended for a day and a half. While banished from class they cleaned up a neighborhood park.