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:
Female mealybugs have only ____ nymphal stages.
answer:
three


question:
Pathologists study four to ____ years after medical school and their postgraduate training.
answer:
five


question:
Humans normally produce only ____ sets of teeth.
answer:

two