The trolleys have been reduced over the last decades, after their initial increase as a public transportation, when new and better ways were discovered/produced for transport, their decline has started.
The buses since their invention, had grown in number and became a very important part of every city's public transportation, and still are.
The rapid transit is the most recent one of the mentioned in here. It's popularity has grown, number increased, and is very practical because it is not causing traffic mess. It is very important transport asset nowadays and makes lives of millions of people much easier.
Answer:
Due to the adverse conditions of poverty and unemployment in the rural areas, people migrate to urban areas. In urban areas they find increased employment opportunities and better living conditions.
Explanation:
answer above
Prior to the existence of the nation-state, Europe was comprised of several multi ethnic empires, the largest and most powerful of which was the Holy Roman Empire. Territory changed hands often. Many times, this took place because of marriage or as a result of war.