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.

[EX Q]: Copper has ____ naturally occurring isotopes.
[EX A]: two

[EX Q]: Most ducks acquire breeding plumage in the fall, ____ or seven months before other birds.
[EX A]: six

[EX Q]: Phosphates are made of ____ phosphorus atom surrounded by four oxygen atoms.
[EX A]:
one