What is a a chromatin

What kind of word is the pronoun in bold letters? the car will be yours when you pay your last car payment.

[he] let his gaze wander to the swirling water of the stream racing madly beneath his feet. a piece of dancing driftwood caught his attention and his eyes followed it down the current. how slowly it appeared to move! what a sluggish stream! what contrasting words are used to describe the stream in this passage?

Why is reasoning relivant to reading and evaluate text?