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: All matter exists in ____ dimensional space, both internal and external.

Answer: three


Question: Plants have roots for ____ main reasons.

Answer: two


Question: Chronic insomnia lasts longer than ____ months and often needs to be treated.

Answer:
three