One reason to join is if you have a struggling economy. The EU is a single trade union, and most of the countries in it use one type of note, called a euro. In joining the EU, a country will be able to be helped by A) The booming EU economy and B) The countries helping each other out. A reason someone might not join the EU is they already have a good economy and don't need help.
Running water and internal drainage systems were used to make them more safe and more sanitary to live in. The workers wages were also increased and workers could find jobs in the city.
