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

[Q]: Diffusion occurs between the capillaries of the _ blood supplies.
[A]: two


[Q]: Sierra County has _ different regions.
[A]: two


[Q]: Weasels are the smallest of the _ mustelids, with a thin, muscular body and a small head.
[A]:
three