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

[Q]: Cleavage is imperfect in _ directions, prismatically.
[A]: two


[Q]: Humans are bipeds who stand between _ to six feet in height when fully grown.
[A]: five


[Q]: Most births produce a single offspring, but twins are born one out of every six or _ births.
[A]:
seven