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.

Niobium occurs primarily in ____ minerals, columbite and pyrochlore.
two

Turkey is a unitary state that brooks ____ claims for minority status by any group.
no

Tropical rainforests have up to ____ layers.

six