Okay. I cannot see the article, again but will try my hardest to answer this anyway.
The purpose can usually be seen in the first sentence or paragraph (unless you have an excerpt). Though it may not be too specific it will usually be backed up by evidence later in the passage. A purpose can always be proven by text details.
Choice of details: should support the purpose
organization: Some things are good for some purposes.
e.g. cause effect, shows the good or bad effects of a purpose. The author can support the purpose or no.
chronological can show how something has changed over time.
etc.
Try to identify the main structure and how the passage is organized and how it supports the main idea.
First you need to know what a sentence fragment is and also what a complete subject and predict is. That should help you.
Th narrator starts the story on who you are.
Answer:
The riots were an explosion of raw anger against the racism and brutality of the police, and the continued denial of basic civil rights.
I dont understand your question, which statements??
