Which verb fits in the first blank to maintain the proper tense and subject-verb agreement?
A. being
B. been
C. be
D. were
Answer:B
Which verb fits in the first blank to maintain the proper tense and subject-verb agreement?
A. being B. been C. be D. were
Explanation: A simplified version of the sentence reads: ''How have (they) been perfected?'' To maintain the consistency of the sentence, 'been' agrees with 'have'.