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.

Many people have ____ symptoms until they suffer chest pains or a heart attack.
no

All orioles have long bills and are about seven to ____ inches long.
eight

Voles are prolific breeders and can produce four to ____ litters a year.

six