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

[EX Q]: Retinoic acid regulates oral epithelial differentiation by _ mechanisms.
[EX A]: two

[EX Q]: Sugar Gliders live between _ and fifteen years.
[EX A]: eight

[EX Q]: Poisons come in _ different forms .
[EX A]:
four