What does this mean in this screenshot i took? what does crusade mean? and what's social change?

Based on its elements, this text teaches readers how to

[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?

What is the rhyme scheme in this excerpt from longfellow's, "the tide rises, the tide falls? " (10 points) the tide rises, the tide falls, the twilight darkens, the curlew calls; along the sea-sands damp and brown the traveler hastens toward the town, and the tide rises, the tide falls.