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

Q: Whales have only _ enemies-man and the killer whale.

A: two
****
Q: Many Asian countries deny entry to travelers whose passports are valid for less than _ months.

A: six
****
Q: Howlers can reach up to _ feet and fifty pounds, with a life-span of possibly thirty years.

A:
four
****