Space

Space is the boundless three-dimensional extent in which objects and events have relative position and direction.^[1] Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensionalcontinuum known as spacetime.อ่านต่อ

Paper

Paper is a thin material produced by pressing together moist fibres of cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. It is a versatile material with many uses, including writing, printing, packaging, cleaning, and a number of industrial and construction processes.
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Deserts

A desert is a barren area of land where little precipitation occurs and consequently living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation. About one third of the land surface of the world is arid or semi-aridอ่านต่อ

Cave

A cave or cavern is a hollow place in the ground,^[1][2] especially a natural underground space large enough for a human to enter. Caves form naturally by the weathering of rock and often extend deep undergroundอ่านต่อ