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.

Q: Plants produce seed at ____ years of age.

A: eight
****
Q: Mollusks have one or ____ hearts.

A: two
****
Q: Cattle require seven pounds of feed in order to gain ____ pound of live weight.

A:
one
****