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:
Copper has ____ naturally occurring isotopes.
answer:
two


question:
Most lemmings are ____ to six inches in length and weigh less than four ounces.
answer:
three


question:
Neurofibromatosis appears in ____ forms.
answer:

two