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: Babies show an interest in solid foods when they are approximately four to ____ weeks old.\Question: Choose the right answer from options given a) nine b) eight c) five d) six

Answer: c


Question: Reverse osmosis uses ____ to ten gallons of water to produce one gallon of drinking water.\Question: Choose the right answer from options given a) two b) zero c) five d) three

Answer: d


Question: Indoor air is usually ____ to one hundred times more polluted than outdoor air.\Question: Choose the right answer from options given a) no b) four c) zero d) five

Answer:
d