Answer:
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth that is part of our solar system.
Answer: Abby wanted her father to have the prettiest disk.
To provide more information or to identify a word, a noun or pronoun is placed with another noun or pronoun, referred to as an <em>appositive phrase.</em>
An appositive phrase may be nonessential or essential.
In essential appositive, the words are not set off with commas.
Whereas, <em>nonessential appositive</em> refers to the addition of meaning in a sentence which is already clear and is set off with commas.
Hence, in the above sentence, the nonessential appositive phrase is 'a dense dead star'. Herein,<em> 'dense dead'</em> are modifiers which modify 'star' and provides detail about it.