Free radicals play an important role in chemical reactions.

The phenyl group plays an important role in organic chemistry.

The carbonyl group plays an important role in organic chemistry.

The carboxyl group plays an important role in organic chemistry.

Compounds containing a propargyl group are often used in organic chemistry research.

Compounds containing acyl groups play an important role in organic chemistry.

The allyl group plays an important role in organic chemistry.

Kihan is my best friend.

The Labor Standards Inspection Office (Rōdō Kijun Kantokusho), or 'Rōki' for short, plays a crucial role in protecting the rights of workers.

This organism has a very complex anlage in the early stages of development.