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: Western medicine uses ____ approaches, drugs or surgery.

Answer: two


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

Answer: one


Question: Walruses can walk on all ____ legs when they are on land.

Answer:
four