How can knowing the history of disease us to understand a. current health problems and b. how health patterns might change in the future?

Knowing the history of a disease can help us understand what causes the spread of the disease, and how the disease can better be controlled. If we know how the disease in manifested in populations throughout history, and if we have developed any new medicines or technology to subsequently treat that disease, that is important knowledge to have in order to manage the disease in the future.

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution