21. The word "they" in line 8 refers to (A) North Americans (B) news shows (C) interviews (D) opinions

27. It can be inferred from the passage that one reason that sociologists may become frustrated with questionnaires is that (A) respondents often do not complete and return questionnaires (B) questionnaires are often difficult to read (C) questionnaires are expensive and difficult to distribute (D) respondents are too eager to supplement questions with their own opinions