By Dan Schwartz / Heights Senior StaffA year ago in Blacksburg, Va., Virginia Tech forced turnovers and plenty of other mistakes by the Boston College offense, en route to a 30-10 rout. Last night, the Eagles returned the favor. BC (5-1, 2-1 ACC), led by a defense that surrendered just 181 yards and forced four turnovers, kept the visiting No. 2 Hokies out of the end zone, winning 22-3.