The bird is flying in the sky.

She wears a hijab every day.

Both of my parents are doctors.

It takes twenty minutes to get to my house.

I was shocked when his duplicity became apparent.

My friend has twin brothers.

In the organic chemistry experiment, we used phthalein as an indicator.

Naphthalene is a compound often used in organic chemistry.

In this experiment, we will observe the crystallization of naphthalene.

Phthalazine is a compound often used in organic chemistry.