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: Some animals can survive freezing, but ____ animals can survive grinding.

Answer: no


Question: Pyrimidines contain one ring and purines contain ____ rings.

Answer:
two