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').

Q: Diarrheal disease kills ____ million children every year.\Question: Choose the right answer from options given a) three b) no c) four d) ten

A: a
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Q: Teething begins for most babies around ____ to six months.\Question: Choose the right answer from options given a) three b) four c) five d) seven

A: b
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Q: Sound waves travel up to ____ times faster through water than through air.\Question: Choose the right answer from options given a) five b) one c) two d) no

A:
a
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