Beginner - irregular singular and plural nouns

She isn't a child, she's __ ________.

They aren't children, they're ______.

He's 8 years old, he's a young _______.

Here are my two _______.

Here's my right _______.

I have many beautiful _______.

The ______ are happy.

They aren't children, they're ________.

Ouch! My _______ hurts!

This is ___ _______.