"This phenomenon is spectacular to see in the night sky," said the professor.
The Grand Canyon is considered to be a natural phenomenon.
A red tide is a natural phenomenon that causes fish to die. The formation of lightning is a phenomenon still not completely understood.
The grand canyon is considered to be a natural phenomenon
Has and have are two forms of the infinitive to have Has is used for he, she and it, and generally speaking third person singular. (eg Richard has a lot of friends) Have is used for all other case...