Answer:
The answers to these questions, would be thus:
1. One very possitive aspect of the Cuban Missile Crisis, was, that it, C: halted the arms race between the United States and the Soviet Union. This happened in 1962, when both the U.S and the USSR came really close to initiating a new war, this time nuclear, on the matter of Russian missiles present on the Cuban nation and American on Turkish land. In the end, both countries are forced to see the risks they are running and both decide to recant, removing missiles on both nations, to avoid new conflict and it brings into the light the danger of the arms race they had engaged in.
2. The key event that led to the whole World War I crisis, was, B: The assassination of the Austrian archduke, Franz Ferdinand, heir to the Austria-Hungary empire, in 1914, by a Serbian hitman. This event only served as the trigger of a dangerous game that had been in play in Europe for several years, especially between Russia and Germany. In the end, the assassination became the trigger that was needed to justify a full-blown war when Germany took advantage and initiated the invasion of other European countries.
3. The direct cause for the U.S finally entering the Second World War, was A: The bombing of Pearl Harbor, and which took place in 1941. This was the year that matters changed, as the U.S, which had been neutral up until then, finally took sides with the Allies and gave this force new strength. It changed the face of the war for everyone and new breath to the Allies.
