Work or death camps located in Germany and Poland to incarcerate and examínate Jews and other "undesirables"

the technology changed agriculture in an impacting manner since many people left the field work by a cellular or other technological appliances

this is a pretty broad question and can be a pretty lengthy answer. since 1900, women have gained a lot more rights and have become active in the workforce. with women being in the workforce, men play a larger role in family life. many family tasks are shared between men and women, whereas, women used to be the sole family caretakers.

that should get you started at least.