What event is considered to be the spark or starting point of the crusades?

Match each person with his contribution. aristotle socrates eratosthenes hippocrates he studied the causes of illnesses in search of cures. he created a teaching method that involved asking questions. he determined that earth was round. he educated alexander the great.

The roman empire created the worlds first

He table below shows the number of immigrants to the united states from different regions of europe between 1871 and 1910