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: Penguins have ____ seasons in their year, as follows.

A: four
****
Q: Collages can have two or ____ layers.

A: three
****
Q: Xenon has ____ valence electrons.

A:
eight
****