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1
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a hollow space underground that's big enough for a person to walk or crawl into.
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3
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air we breath
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4
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a shortage of rainfall
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7
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the introduction of harmful substances or products into the environment
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8
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the gaseous envelope surrounding the earth; the air.
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9
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a field where grass or alfalfa are grown to be made into hay
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10
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a dense forest in a tropical region.
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11
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a barrier constructed to contain the flow of water or to keep out the sea
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12
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animals that are dying because their habitat are being damaged and will die.
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15
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the rising of a body of water and its overflowing onto normally dry land
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16
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long and narrow strip of water made for boats or for irrigation
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17
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a passageway through or under something, usually underground (especially one for trains or cars)
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1
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a deep valley with steep sides, often with a stream flowing through it.
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2
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a natural stream of water smaller than a river
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5
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the rise in temperature caused by gases in the atmosphere.
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6
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forest A forest is a densely wooded area, or land covered with trees
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13
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polluted water falling from the sky.
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14
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the power that comes from coal, electricity and gas, that is used for producing heat.
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