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

[Q]: Trees can also be air layered but air layering usually takes four to _ months to be successful.
[A]: six


[Q]: Chaotic systems have at least _ solutions.
[A]: two


[Q]: Some babies sleep more than that, maybe for _ or ten hours at a time.
[A]:
eight