What? What is the context
Hoover Dam, it provided western United States with much electricity
I believe that the answer is b
For hundreds of years education in the Roman Empire was done within the families by the parents or Greek slaves who were very educated. As education advanced it was made available to everyone although there was no attendance policy. Slowly the family began to loose power and children were being sent away to proper schools. That would lead me to believe it could be (d).
D. The division of Germany into two countries
