Question

Io, one of Jupiter’s moons, is dotted with active volcanoes. Which word or phrase is an appositive in the sentence?

Answer 1

“one of Jupiter’s moons” is the appositive phrase. A trick to finding those is that appositive phrases are always surrounded by commas (called the comma rule)!
-hope this helps <3

Answer 2

The answer to your question would be that hte appositive phrase in this sentence is "one of Jupiter's moons".

Step-by-step explanation:

An appositive is a noun or noun phrase that renames another noun right beside it. Nonessential appositives are always separated from the rest of the sentence by means of commas, as in this example. As the information they provide is not relevant to complete the meaning of the sentence or to identify the noun they modify, they are offset with commas.