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:
Natural ytterbium is a mixture of ____ stable isotopes, with seven other unstable isotopes known.
answer:
seven


question:
Alcohol content is ____ to three times more than beer.
answer:
two


question:
Hunger afflicts ____ out of seven people on Earth.
answer:

one