He performed a circus act on a unicycle.

Quinoxaline is one of the important compounds in organic chemistry.

I went to watch a curling match.

The Hanlin Academy was one of the most important academic institutions in Chinese history.

He is interested in learning the techniques of cunnilingus.

In chemical experiments, we use a graduated cylinder to measure the exact amount of liquid.

Have you ever seen a helicopter hovering?

The drone is hovering in the air.

He is bilingual, able to speak both English and Japanese fluently.

He received bilingual education and can speak English and Japanese fluently.