In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

Q: Humans host _ species of louse, the head louse , the body louse and the pubic louse .

A: three
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Q: Tourism is among the _ largest industries in each of the western states.

A: three
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Q: Some homes have three or even _ computers from which they can access the Internet.

A:
four
****