Alkenes, also known as olefin hydrocarbons, play an important role in organic chemistry.

Alkynes play a very important role in organic chemistry.

In chemistry class, I learned about alkanes.

Alkenes play a very important role in organic chemistry.

He is from the Caucasus region.

She went to the party wearing her new coatdress.

Since it started raining, I put on a raincoat.

This coaster is my favorite.

He is preparing the props to use on stage.

My new apartment is on the third floor of the co-op.