The compass, the astrolabe (instrument used to measure latitude), and the rudder <span>all helped European explorers on their quest to find Asia and get rich by by </span><span>buying spices there and selling them in Europe to get a profit.
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Economic productivity has declined in some countries as a result of : Bubonic Plaque
In the past, Bubonic plaque manage to kill about 25 - 30 % of the world population, these greatly decrease the number of workers that could contribute to production activity and reduce Overall economic productivity in several countries
This should be at the math section not the history. But the answer is 17 quarters.