C) how are living conditions in the twenty-first century different than conditions in the nineteenth and early twentieth centuries?

In general, living conditions have greatly improved during this time due mostly to technological advances that allow products to be produced for less money. A great amount of poor nations still exist, however. 

Very useful. it is to learn because history repeats itself so learning about it those mistakes not happen again.

Iwould like a photo instead of all this and you can’t just go out asking for a paragraph thinking someone will be like oh yeah here it is