I do believe those are correct.
He gets scared. it really rattles him, mentally
The answer is number 4) These numbers show that teenagers care about others.
Sentences 1-3 show evidence to support the main argument, which is that teenagers help others. Sentence 1 gives an individual example, and on sentences 2 and 3, it presents statistical data.
Segregation; the two different races are being segregated (separated) from each other. Hope this helps :)