The vault was a structure consisting of arrangements of arches which allowed the Romans to connect any room with the arches because they usually formed a ceiling or roof
Abu-Bakr spread Islam by defeating the people that went against him and converted them to Islam. If they did not convert he would murder them.
The major way in which border areas of the west were affected by the mixture of people is that a plethora of immigrants from all over the world wanted to expand to the west in order to settle--meaning that people from all backgrounds often fought over land and job opportunities.
During the Cold War there was a concern in the United States over the expansion of communism. This fear of communism manifested itself in the domino theory an idea which governed much of us foreign policy starting in the 1950s. The domino theory was essentially the idea that if one nation fell to communism its neighboring counties would as well and this process would repeat itself almost resembling a row of dominos falling (hence the name). Because of this theory many political leaders in the us feared that if former French colonies like Vietnam fell to communism than their neighboring counties would as well including Laos, Cambodia, etc.
It was "Philippe Bunau-Varilla" who <span>was the engineer in charge of building the canal through Panama for the French, although he had help from other engineers as well. </span>
