source: The Fairmount Line is undergoing a major rehabilitation that includes the construction of four new stations in Boston, while work on a new western terminus of the Fitchburg Line at Wachusett Station has started.
target: The Fairmount Line is undergoing a major rehabilitation. Four new stations will be constructed in Boston.  Work on a new terminus at Wachusett Station has started. The terminus is part of the Fitchburg Line.
references: The Fairmount Line is undergoing a major rehabilitation. Four new stations will be constructed in Boston.  Work on a new terminus at Wachusett Station has started. The terminus is part of the Fitchburg Line.