How is she doing?
She is happy.
How is it doing?
It's hot.
How are you?
I am cold.
How is it doing?
It is tired(sleepy).
How are they doing?
They are scared.
How is he going?
He is (very) hungry.
Are this boy and girl sad?
No, they aren't. They are in love.
Is he upset?
Yes, he is.
Are these girls happy?
No, they aren't. They are sad(upset).
Is she angry?
Yes, she is.