What is a bureaucracy?
a. a group of officials who run a government or other organization
b. a hereditary ruling class
c. a densely packed battle formation used by the athenians
d. a city-state of ancient greece

an expansion is one of two basic business cycle phases; the other is contraction. the transition from expansion to contraction is a peak, and the changeover from contraction to expansion is a trough.

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.