what are the relations between Christians, Muslims, and Jews today? How might these relations have been affected by events in the Middle Ages of Europe?
please help me
That first question is not one that has an easy answer. Here are search results that show how complex the entire topic is:
http://www.google.com/search?q=christians+muslims+jews+today&rls=com.microsoft:en-us:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA
To work on the second question, you need to consider the Crusades. Go to Wikipedia read about that period of time in the Middle East: http://en.wikipedia.org/wiki/Crusades Note the dates. This conflict has been going on for a long time, taking different forms.
The relations between any religions is actually a matter of where and when those people are living. As for your second question, the very word, CRUSADE, has different connotations in the Middle East and America. Here it means working forcefully toward a particular goal (a crusade against cancer), while people in the Middle East hear "Kill the Muslims!" which is a result of the crusades against the Muslims centuries ago when Christian knights proudly slaughtered anyone living in the Middle East.