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

[EX Q]: Lobsters have _ walking legs and two legs bearing claws.
[EX A]: eight

[EX Q]: Pure water contains _ ions and is therefore a nonconductor .
[EX A]: no

[EX Q]: Most adults sleep between seven and _ hours a night.
[EX A]:
eight