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Question 1 1. During the _____ phase of the water cycle, water that does not run into rivers, get absorbed by plants, or evaporate seeps deep into the soil and increases the amount of groundwater--which is purified by a natural filtration cycle and is drinkable.
Question 2 2. The _____ theory proposes that our moon was formed somewhere else in the universe, but it wandered near enough that Earth's gravitational field pulled it into an inescapable rotation around Earth.
Question 3 3. When oceanic plates collide with continental plates and the oceanic crust sinks below the continental crust, we call this process _____.
Question 4 4. Which type of glacial erosion happens when rock that is frozen to the base and back of the glacier scrapes or grinds against bedrock?
Question 5 5. _____ rock is formed when particles of sand, shells, and fragmentary stony materials accumulate in layers and harden.
Question 6 6. The _____ is Earth's viscous, easily deformed region which lies at depths between approximately 50 and 120 miles below the surface. It is always in an almost solid state, though some regions are actually molten.
Question 7 7. The _____ explains that a mass moving in a rotating system experiences a force acting perpendicular to the direction of motion and to the axis of rotation. This discovery is important for the understanding of cyclonic weather systems.
Question 8 8. _____ clouds are mid-level, grayish or blue-gray clouds that almost always cover the whole sky when they appear. The Sun or the Moon may shine through these clouds and appear watery or fuzzy to the human eye. When seen, a storm with continuous rain or snow is likely coming.
Question 9 9. _____ is the gaseous molecule of three oxygen atoms which shields us from the sun's radiation. Naturally found in the stratosphere, when it occupies the troposphere we consider it an air pollutant.
Question 10 10. A.I. Oparin believed that Earth's atmosphere was a dynamic and reactive agent which, alongside UV radiation, lightning, and the organically rich oceans referred to as _____, eventually caused a series of reactions which transformed simple compounds into more complex life forms.
Question 11 11. When the hydrogen fuel that powers nuclear reactions within a star depletes, the star will begin the final phase of its lifetime. Over time, the star will expand, cool and change color to become a _____.
Question 12 12. During _____ certain bacteria convert nitrogen gas in the atmosphere into ammonia (a plant nutrient) which enters the ecosystem from the atmosphere.
Question 13 13. The four planets closest to the Sun (Mercury, Venus, Earth, and Mars) are small, warm, rocky worlds, that have few (or no) moons and no ring systems. We refer to these planets as _____.
Question 14 14. Marie Curie discovered that unstable atoms lose energy, or decay, by emitting radiation in the form of particles or electromagnetic waves. Ernest Rutherford showed how this decay process could act as a clock for dating old rocks. Arthur Holmes developed the technique of dating rocks using the uranium-lead method. Today we utilize _____, which is the method of dating geological or archaeological specimens by determining the relative proportions of specific radioactive isotopes present in a sample of stone, earth, or even man-made materials.
Question 15 15. When humans and animals feed on the carbon in plants and exhale carbon dioxide formed during respiration, or when humans and animals and plants die, are eaten by decomposers, and the carbon in their bodies is returned to the atmosphere as carbon dioxide, we recognize these processes as essential parts of _____.
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