WASHINGTON, D.C. A group of Cobb School students recently returned from a 10-day trip to Washington, D.C., Gettysburg, Philadelphia, New York and Boston. The middle school students visited the Martin Luther King memorial and Rep. Peter DeFazio’s office in Washington. They also drove through Amish country, saw the Liberty Bell in Philadelphia, visited the Sept. 11 memorial in New York City and saw Spiderman on Broadway. The students walked the Freedom Trail in Boston and visited the Mayflower and Plymouth Plantation. …