instruction:
In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
question:
Morocco has _ perennial rivers and many dams have been built with potential for power generation.
answer:
four


question:
Smokers die an average of six to _ years earlier than nonsmokers.
answer:
eight


question:
Some spiders have up to six or _ or twelve eyes.
answer:

eight