"Quincentennial" Natural Recordings by Native Speakers
The word "quincentennial" refers to a 500th-anniversary celebration. It is often used to describe a period of commemoration that takes place every 500 years.
Quinazoline is a type of heterocyclic aromatic organic compound that contains two adjacent nitrogen atoms in a single six-membered ring, fused to either a five-membered or a six-membered benzene ring. It is related to the benzoquinazoline class but the two benzene rings are in the 1,4 positions.