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Across 4. the interface between the stratosphere and the ionosphere 5. term that describes the upper limit of the troposphere 7. this layer contains only a small account of earths atmosphere that can be 1000 10. the lowest region of the atmosphere, extending from the earths surface to a height of about 3.7-6.2 miles 11. term that describes the edges of rivers and streams 12. the outermost region of a planets atmosphere where helium and hydrogen gas are found

Down 1. this layer is made up of primarily concentrated ozone. 2. all land drained by a river stream or lake 3. this is the name of the river basin that serves columbus county nc 6. this layer contains most of the mass of the atmosphere including water vapor 8. the region of the earths atmosphere above the stratosphere and below the thermosphere between about 30 and 50 miles 9. the land that water flows across or under on its way to a river. (2 Words)