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

[EX Q]: Woodchucks can dig up to _ entrances to one den.
[EX A]: three

[EX Q]: Atoms are most stable when they have _ electrons in their outer electron energy level.
[EX A]: eight

[EX Q]: Smells reach the olfactory sensory neurons through _ pathways.
[EX A]:
two