Do we have social mobility?

English homework:
Do we have social mobility? / Is it possible to change classes?

Yes, changing classes is possible in postmodern communities like the german. But usually it's very difficult to get a good education, if you are poor. Parents have - for example - to pay for books, school trips etc. People living in poor quaters are often treaten different - of course in a negative meaning - compared with opulent pupils. Also many people, whose parents or maybe themselves came from a different country to Germany, usually don't get a good education! Vernor Muñoz, Special Rapporteurs of the UN for education said that the german schoolsystem is discreminating poor kids, migrants and handicapped people.

I think the question is wrong. The right question would be: "Why do we have classes and would live without classes be better?"
Maybe I'll answer these questions...anytime.