I think it keeps them warn since it is a mane. I could be wrong though
To see the different views of society at the time. Also, if the works are of different places and social class, you can compare how all types of people saw the world then.
Every 4th graders should have a 5th grade class but nature has great class because that is probably need one of the classrooms
And + The are articles, if definite articles are included, if not then just 'and'