By the end of the Middle Ages, Arthur's fifth-century foot soldiers had become knights on horses; his fortified hills had become grand castles; and his court had become Camelot, a chivalric utopia. What is the appositive in the sentence and what does it modify?

a chivalric utopia

Explanation:

An appositive is a noun that follows another noun in order to provide more information about the noun.

With regards to the question, the appositive is "a chivalric utopia". Here, the appositive is used to modify the main noun which can be found in the last part of the sentence that is, Camelot. It gives more information on Camelot.

the sun warms our planet, and with the moon, creates the tides. the moon orbits the earth and in turn, the earth orbits the sun. because they appear to be the same size in the sky, the sun, earth and moon work together to create eclipses. when the moon is directly in between the earth and sun