Ammonia and urea are the reagents used along with a catalyst to remove NOX from the flue gas stream.
Ammonia works with a catalyst.
Ammonia is a catalyst
The artists are outdoors.
The player is playing soccer.
The man was not alone.
Three players wear identical uniforms on a basketball court.
The evolutionary approach to product development was only used by a few of the companies visited.
You say you were in Sherman?