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

[Q]: White sturgeon inhabit _ large river systems, all on the western coast of North America.
[A]: three

[Q]: Sturgeons are shark-like in form but are unique in having _ rows of bony plates along the body.
[A]: five

[Q]: Guillemots are fed sprats _ or four times a day and are constantly checked by vets.
[A]:
three