Can you tell me the answer please

What is one way that shakespeare uses source material in othello? to establish lago's jealous natureto describe why lago loves the moor's wifeto illustrate lago's skill on a battlefieldto explain how lago became so close to the moon

[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?

Based on this excerpt, the reader is able to conclude that turner feels about his friendship with lizzie.