"How does outer-core convection generate the magnetic field?"
What will be an ideal response?
Answer: "The shape of Earth's magnetic field resembles that produced by a laboratory bar magnet. Geologists know from the lines of magnetic force that the field originates deep within Earth, where temperatures are too high for the existence of permanently magnetized material. The magnetic field must be continually generated by the geodynamo- rapid convective motion of electrically conductive, iron-rich liquid in the outer core. Complexities in rapid outer-core convection caused by electrical conductance through the inner core and transfer of heat from the outer core to the mantle may account for rapid fluctuations in the strength and orientation of the magnetic field and even reversals of the field."
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Which of the following statements about landfill processes is false?
A. Open landfills are common near major cities in many developing countries. B. Contaminated leachate can seep from the bottom of landfills. C. Contaminated groundwater is a problem at some landfills. D. Fly ash created in landfills is a useful by-product. E. Older, unlined landfills may have particularly bad water pollution problems.
An increase in Earth's albedo would.
Which of the following was a prime factor for the economic collapse in Eastern Europe immediately following the end of the Cold War?
A) the nations of Eastern Europe were forced to pay back massive loans which they had taken out from Germany, France and England B) the removal of Soviet troops translated into a major loss of revenue from soldiers spending their paychecks in the local economy C) the markets of Western Europe stopped buying products from Eastern European nations D) the devastation of bombing from the Cold War between 1945 -1989 had reduced Eastern Europe into ruins E) the loss of subsidized natural gas and oil from the Soviet Union coupled with the collapse of Soviet markets made it impossible for Eastern European industries to operate and compete
In science, the term theory is ________
A) a first guess B) an unsupported hunch C) a revolution around the Earth D) not relevant E) a well-tested explanation for a natural phenomenon