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

[Q]: Plants have many white flowers with _ petals, giving the plant a white, flat-topped appearance.
[A]: four


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


[Q]: Women have a _ times greater chance of developing osteoporosis than men.
[A]:
four