Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.
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Question: Elephants give birth to ____ calf every four to nine years on average.

Answer: one


Question: Pertussis is highly contagious with symptoms that can linger six to ____ weeks.

Answer: ten


Question: Embryonic endoderm lines ____ tubes within the body.

Answer:
two