QUES: Though there is no doubt that the demographic crisis of the 14th century caused a dramatic fall in production and commerce in absolute terms, there has been a vigorous historical debate over whether the decline was greater than the fall in population. While the older orthodoxy held that the artistic output of the Renaissance was a result of greater opulence, more recent studies have suggested that there might have been a so-called 'depression of the Renaissance'. In spite of convincing arguments for the case, the statistical evidence is simply too incomplete for a definite conclusion to be made.

What caused the decrease in commerce and production in the 14th century?
What is the answer?
ANS: demographic crisis
QUES: The Appalachians are also home to two species of fir, the boreal balsam fir (Abies balsamea), and the southern high elevation endemic, Fraser fir (Abies fraseri). Fraser fir is confined to the highest parts of the southern Appalachian Mountains, where along with red spruce it forms a fragile ecosystem known as the Southern Appalachian spruce-fir forest. Fraser fir rarely occurs below 5,500 ft (1,700 m), and becomes the dominant tree type at 6,200 ft (1,900 m). By contrast, balsam fir is found from near sea level to the tree line in the northern Appalachians, but ranges only as far south as Virginia and West Virginia in the central Appalachians, where it is usually confined above 3,900 ft (1,200 m) asl, except in cold valleys. Curiously, it is associated with oaks in Virginia. The balsam fir of Virginia and West Virginia is thought by some to be a natural hybrid between the more northern variety and Fraser fir. While red spruce is common in both upland and bog habitats, balsam fir, as well as black spruce and tamarack, are more characteristic of the latter. However balsam fir also does well in soils with a pH as high as 6.

How many species of oaks are found in the Appalachians?
What is the answer?
ANS: unanswerable
QUES: Von Neumann's principal contribution to the atomic bomb was in the concept and design of the explosive lenses needed to compress the plutonium core of the Fat Man weapon that was later dropped on Nagasaki. While von Neumann did not originate the "implosion" concept, he was one of its most persistent proponents, encouraging its continued development against the instincts of many of his colleagues, who felt such a design to be unworkable. He also eventually came up with the idea of using more powerful shaped charges and less fissionable material to greatly increase the speed of "assembly".

Did von Nemann think that the atomic bomb design was not workable?
What is the answer?
ANS:
he was one of its most persistent proponents, encouraging its continued development