I believe it is Religious Beliefs
Blacks had to carry passes at all times and live on "reserves"
The topic is very controversial because there are several viewpoints.
Some people believe that Mexican immigration has become extremely high, and that it must be somehow restricted. Other people may argue that some Mexicans work jobs that most other people would not want to do. Some of these include working on farms or other dirty jobs.
These opposing viewpoints cause the topic of Mexican immigration to be highly controversial.
The answer to this is A.korea
It was used as an engine in locomotive trains, & also in steam boats. it also helped create electricity which allowed things such as morse code & synchronization of the world’s clocks.
