During summer, wildfires are relatively common occurrences in the mountains of the western United States. We have learned that Earth is a system in which various parts of the four major spheres interact in uncountable ways. Let’s relate that idea to a wildfire in the western mountains.

a. What atmospheric conditions might have preceded and thus set the stage for this wildfire?
b. What might have ignited the blaze? Suggest a natural possibility and a human possibility.
c. Describe at least one way that wildfires, like the one shown here, might influence future mass-wasting processes.

Which of the following regions suffers the most from acid rain? a. the area around vancouver c. the area below atlanta b. the area below detroit d. the area above montreal

Scientist: cross-sections of stalactites—calcite formations deposited on cave ceilings by seeping water—can reveal annual variations in rainfall in particular areas over hundreds and thousands of years. we often found that when—according to these cross-sections—drought occurred in a particular area, it coincided with the collapse of an ancient society in that area. i hypothesize that drought reduced agricultural productivity in these areas, thereby leaving these societies without the resources needed to handle internal stresses and external threats. which of the following, if true, would most weaken the support for the scientist's hypothesis? a. many droughts indicated in the cross-sections of stalactites do not correspond with the collapse of a society in that area. b. information from the cross-sections of stalactites alone cannot reveal the level of agricultural output in an area at a particular time. c. most of the societies that collapsed during droughts did so when internal power struggles coincided with military raids from neighboring societies. d. most of the societies that collapsed during droughts maintained large stockpiles of food and water at the time of their collapse. e. information from stalactites also suggests that the collapse of some societies coincided with periods of abnormally high rainfall.

What was the role of european colonies during the industrial revolution