Inner city residents who are trapped in an unending cycle of hardships are referred to as
A) permanent welfare recipients.
B) permanently unemployed persons.
C) permanent hardship cases.
D) permanent victims.
E) a permanent underclass.
Question 2
What best explains the differences in the density gradients between 1930 and 1990 in Figure 13.9.2?
A) Suburbs grew rapidly in the second half of the 20th century along with construction of apartments and town-house projects in the periphery of the CBD.
B) More jobs were created in the CBD and hence more people chose to live in the CBD by 1990.
C) The outermost gradients reduced in density by 1990 because of encroaching agriculture.
D) Improvements in mass transportation allowed people to move from the suburbs towards the CBDs between 1950 and 1990.
E) Cities implemented restrictions on cars in the CBD and adjacent gradients starting in 1950. This resulted in a higher density living in the CBD by 1990.
The phosphorus cycle. Numbers are 1012 g P or fluxes as 1012 g P per year (data from Schlesinger 199
History of the number of observed sunspots during the last 250 years, which shows the ~11-year solar
Carbon Cycle
Urea cycle
The Sunspot Cycle
The cardiac cycle