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.

Cattle can have up to six to ____ years of grazing, after which a scrub savannah grows up.
ten

Copper has ____ naturally occurring isotopes.
two

Arctiid moths deal with echolocating bats in ____ ways.

two