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

[EX Q]: Flatworms exhibit _ forms of life styles, free-living and parasitic.
[EX A]: two

[EX Q]: Pollination is accomplished only by insect-agency, and where insects fail _ fruits are ripened.
[EX A]: no

[EX Q]: Granite conducts sound _ times faster than air.
[EX A]:
ten