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crater – n. a large hole in the ground
geologist – n. a scientist who has studied rocks and soil in order to learn about the history of planets
cliff – n. an area of high, steep rocks
sediment – n. a solid substance that forms a layer at the bottom of a liquid
resolution – n. a measure of sharpness for an image
three-dimensional – adj. appearing to have length, depth and width
terrestrial – adj. relating to the Earth, not space
host – v. to serve as a host for something
puzzle – n. a game or activity in which you have to put pieces together or answer questions using skill
crucial – n. extremely important or necessary
