AMHERST - A middle school science fair is no place for a BB gun. That's what Amherst Regional Middle School eighth-graders Nathan C. Woodard and Nathaniel A. Gorlin-Crenshaw were told by officials from the Massachusetts Middle School Science Fair. The message came just 10 days before the June 4 event at Worcester Polytechnic Institute. "We had everything ready except gluing the poster," said Nathan, who lives in Pelham. "We got an e-mail that the project was hazardous, and it couldn't be shown because they didn't want to encourage kids to use ballistics." The rejection came after the two teenagers spent...