| Front | Back | 
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								What causes the Earth's equatorial bulge?									 | 
								The Earth's rotation									 | 
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								What causes the Earth's spherical shape?									 | 
								The Earth's gravity									 | 
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								Which following provides significant information about the composition of the Earth's interior?									 | 
								Only analysis of the Earth's density and study of the seismic waves are correct choices.									 | 
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								Which of the following is the most abundant gas in the Earth's atmosphere?									 | 
								Nitrogen									 | 
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								What causes precession?									 | 
								The gravitational interaction of the Sun and of the Moon with the equatorial bulge of the Earth.									 | 
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								What property of the seismic waves allows scientists to derive information about the Earth's interior?									 | 
								Both the S waves can propagate only through solids and the speed of the seismic waves through a material depends on the nature of the material are correct.									 | 
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								What is the mechanism that produces the Earth's magnetic field?									 | 
								The combination of the Earth's rotation and convection currents in the Earth's molten core.									 | 
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								What is the origin of oxygen gas in the Earth's atmosphere?									 | 
								It was produced by photosynthesis.									 | 
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								Which of the following demonstrates that the Earth spins around an axis?									 | 
								The Coriolis effect									 | 
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								Which of the following result from the Coriolis effect?									 | 
								All of the choices are correct									 | 
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								Suppose that we have a sample of 20 atoms of radioactive potassium. How many atoms of calcium do you expect to find in this sample after 1.3 billion years?									 | 
								9									 | 
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								What causes the hot inner part of the Earth's core to be solid and not liquid?									 | 
								The extreme pressure at the inner core causes the atoms to hold in place together and form a solid.									 | 
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								Which of the following is true about ozone?									 | 
								All of the choices are correct.									 | 
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								Which of the following is true about the Earth's magnetic field?									 | 
								All of the choices are correct.									 | 
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								The __ type seismic waves can travel through liquids. The __ type seismic waves can travel through solids only.									 | 
								P; S									 |