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

[EX Q]: Wild alfalfa is fairly drought resistant, with roots going down _ feet.
[EX A]: ten

[EX Q]: Most people stay three or four years, sometimes _ or six years.
[EX A]: five

[EX Q]: Marine fisheries cause changes at _ levels of organization of biodiversity.
[EX A]:
three