Genetic mutations .
a. can occur naturally
b. are always passed on to the next generation
c. are most common in body parts that are used frequently
d. are mainly caused by diseases associated with fetal development

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.