An adjective phrase is a group of words that describe a noun or pronoun in a sentence. The adjective phrase can be placed before, or after, the noun or pronoun in the sentence.
Example:
The painter is a person of immense talent.
(Person = noun)
(Of immense talent = adj. phrase)
Source: yourdictionary.com
Answer:
it is the library, which IS essential to me
Because the space shuttle is moving at a fast speed.
