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sediment – n. a solid substance that forms a later at the bottom of a liquid
geologist – n. a scientist who studies the history of the earth and its life, especially as recorded in rocks
preserve – v. keep something the same or keep it from being damaged or destroyed
network – n. an interconnected or interrelated chain, group, or system
clay – n. a heavy, sticky material from the earth that is made into different shapes and that becomes hard when it is baked or dried
drill – v. make holes in hard materials with a machine
