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

[EX Q]: Indoor cats can live up to _ times longer than an outdoor cat.
[EX A]: seven

[EX Q]: Tarantulas molt as many as _ times in some species.
[EX A]: nine

[EX Q]: Natural rhenium is a mixture of _ stable isotopes.
[EX A]:
two