Families and ethnic groups were separated.
Germany had to reduce the size of its army, pay reparations to European countries, reduce its arsenal of weapons, and assume full responsibility for the war.
Low population and others that include less people
The americans
It made Germany reduce its military. (APEX)
Merchants could protect themselves by banding together. To reduce the threat of attacks
to reduce pollution
Factories were located close to railroads so as to facilitate and reduce the cost of shipping their products.
They allowed Europeans to communicate easily across different parts of international empires.
The factories should be built away from cities.
towns are many pollution in factories,vehicles etc,etc .
To reduce travel time, costs and hazards.
International treaties reduce war, which reduces the need for guns, gunpowder, tanks, and metal. Factories that make these war items dump their sewage in oceans, and if there is no demand for such products then the factories don't make them and they don't have sewage to dump.
You would put a lubricant - oil or grease - between the moving parts.
People do care and are starting to care more and more, factories especially in developed countries are becoming more environmentally friendly and using cleaner technologies to reduce pollution
To reduce shipping expenses and time to processing. This keeps costs down.
The political problems reduce foreign investment
reduce the time it took to transport goods