We need things consumed, burned up, worn out, replaced and ______ at an ever increasing rate.

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