Phthalazine is a compound often used in organic chemistry.

My zodiac sign is Gemini.

He was born under the sign of Gemini.

They are twin brothers.

I am looking forward to the day we meet again.

Again, he started that story.

Where is the lid for this pot?

She is a twin sister.

He was like a double-dealer, expressing different opinions to two groups.

His jet is equipped with an afterburner.