Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').
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Question: Real airplanes have round engines and ____ wings.\Question: Choose the right answer from options given a) four b) six c) three d) two

Answer: d


Question: Songbirds have ____ sets of vocal chords.\Question: Choose the right answer from options given a) six b) two c) eight d) ten

Answer: b


Question: Termite colonies can number up to ____ million inhabitants.\Question: Choose the right answer from options given a) six b) four c) three d) one

Answer:
c