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

[EX Q]: Most polyps cause no symptoms and take five to _ years to change to cancer.
[EX A]: seven

[EX Q]: Merlin is about five and _ half inches long.
[EX A]: one

[EX Q]: Flamingos belong to the genus phoenicopterus, and there are _ different species of flamingos.
[EX A]:
six