Scientists theorize that australia was once part of a larger mainland area but due to plate tectonics, broke away. according to island theory, scientists can explain all but one of these occurrences as a result of australia becoming and staying an island for a very long time. that is
a) extremes in size, large or small.
b) the evolution of flightless birds.
c) the presence of relics, like the marsupials.
d) a large assortment of plant dispersal mechanisms.

Which of the following is true? a. under the current unemployment insurance system, benefits replace about 90 percent of the typical worker's prior pretax earnings. b. high benefit payments to unemployed workers will tend to increase the rate of unemployment. c. if a system of personal savings accounts replaced the current unemployment benefit system, the unemployment rate would fall to zero. d. the rate of unemployment in the large european economies has been persistently lower than that of the united states due to their more generous unemployment benefits.