Oxford Discover Book 4 - Units 1, 2, and 3

He studies the space.

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He studies the past.

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They fight to protect a nation.

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They travel to explore the space.

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He rules a group of countries.

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These are artifacts made of clay.

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A comet is a bright object with a long tail that travels around the sun.

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An asteroid is a large, irregularly shaped object in space that orbits our Sun.

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A meteorite is a piece of matter from space that has landed on earth

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The Moon is the natural satellite of the earth, visible (chiefly at night) by reflected light from the sun.

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