President Chester A. Arthur signed the Chinese exclusion act in 1882 which banned Chinese immigration to the United States for a total of 40 years.
When the Turks invaded the Byzantine Empire, the Holy Lands which were a part of the empire, were overrun also. This led to Alexius I asking the Pope for Christian knights to help him in the Crusades which led to Pope Urban II to allow the Crusades to happen.
The correct answer is <span>better standards for public health
Thanks to his work with bacteria, it was made possible to make things clean and consumable and safe for humans. This meant fewer deaths and a longer life span, which led to greater standards for public health in general. It was a great achievement for people because they would live through common things that used to kill them.</span>