CREATE TABLE "united_states_house_of_representatives_e" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" real,
  "result" text,
  "candidates" text
);

Question: what is the district with the candidates edward boland (d) unopposed?
SQL: SELECT "district" FROM "united_states_house_of_representatives_e" WHERE "candidates"='Edward Boland (D) Unopposed';

Question: what is the party where the candidates are edward boland (d) unopposed?
SQL: SELECT "party" FROM "united_states_house_of_representatives_e" WHERE "candidates"='Edward Boland (D) Unopposed';

Question: what is the party where the incumbent is edward boland?
SQL: SELECT "party" FROM "united_states_house_of_representatives_e" 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 "united_states_house_of_representatives_e" WHERE "candidates"='Paul Tsongas (D) 60.6% Paul W. Cronin (R) 39.4%';