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: African music has as many as ____ rhythms in command at once.

A: four
****
Q: Exposure can occur in ____ general ways, ingestion, skin contact and inhalation.

A: three
****
Q: World population reaches ____ billion.

A:
four
****