A．canceled
B．dissipated
C．discarded
D．concealed

A．They were being kept prior to the seventeenth century.
B．They mention only epidemics of smallpox.
C．They provide quantitative and qualitative evidence about Native American populations.
D．They prove that certain diseases were unknown in the pre-Columbian New World.

A．to provide support for a hypothesis
B．to reconcile opposing viewpoints
C．to refute a common misconception
D．to analyze an argument in detail

A．demonstrate the impact of modern medicine on epidemic disease
B．advocate new research into the continuing problem of epidemic disease
C．confirm the documentary evidence of epidemic disease in colonial America
D．refute allegations of unreliability made against the historical record of colonial America

A．recur more frequently than chronic diseases
B．involve populations with no prior exposure to a disease
C．usually involve a number of interacting diseases
D．are less responsive to medical treatment than are other diseases

A．were immunologically defenseless against measles
B．could scarcely ward off the fatal attack by the 1952 epidemic
C．were the last native people to be struck by a virgin-soil epidemic
D．didn't come into frequent contact with White Americans until the 20th century

A．eleven years old
B．sixteen years old
C．twenty-one years old
D．between twelve and twenty-one years old

A．in the late 19th century in the United States the dividing line between adolescence and adulthood no longer existed
B．no one can marry without the permission of his parents until the age of twenty-one
C．one is not free from the restrictions of child labor laws until he can join the army
D．one is considered to have reached adulthood when he has a driver's license

A．the older one becomes, the more basic rights he will have
B．one won't get more basic rights than when he was 21
C．one will enjoy more rights granted by society
D．one will obtain more basic rights

A．graduations from schools and colleges
B．social recognition
C．socio-economic status
D．certain behavioral changes