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]: Many addicts use opium because they have ____ access to public health care facilities.
[EX A]: no

[EX Q]: Cytochrome oxidase consists of two cytochromes and ____ copper atoms.
[EX A]: two

[EX Q]: Water is visualized as occupying the center of a tetrahedron, a solid with ____ faces.
[EX A]:
four