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

[EX Q]: Scientists use a characteristic to classify animals into _ groups.
[EX A]: two

[EX Q]: Chlorine is manufactured in _ ways.
[EX A]: two

[EX Q]: Crawlers are minute, orange-yellow and oval, with _ legs and one pair of antennae.
[EX A]:
six