Question: what is the district with the candidates Edward Boland (D) Unopposed?
SQL: SELECT "District" FROM "1-1341690-21" WHERE "Candidates" = 'Edward Boland (D) Unopposed';

Question: what is the party where the candidates are Edward Boland (D) Unopposed?
SQL: SELECT "Party" FROM "1-1341690-21" WHERE "Candidates" = 'Edward Boland (D) Unopposed';

Question: what is the party where the incumbent is Edward Boland?
SQL: SELECT "Party" FROM "1-1341690-21" WHERE "Incumbent" = 'Edward Boland';

Question: How many times was the candidates Paul Tsongas (D) 60.6% Paul W. Cronin (R) 39.4%?
SQL: SELECT COUNT("Incumbent") FROM "1-1341690-21" WHERE "Candidates" = 'Paul Tsongas (D) 60.6% Paul W. Cronin (R) 39.4%';