instruction:
Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.
question:
International mail consists of ____ categories of mail.
answer:
three


question:
Arthropods are made up of ____ groups of living animals and one group of extinct animals.
answer:
four


question:
Most people tan ____ to three times a week.
answer:

two