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.อ่านเพิ่ม

Deserts

Far from being barren wastelands, deserts are biologically rich habitats with a vast array of animals and plants that have adapted to the harsh conditions there. Some deserts are among the planet's last remaining areas of total wilderness. Yet more than one billion people, one-sixth of the Earth's population, actually live in desert regions. อ่านเพิ่มเติม

Cave

For other uses, see Cave (disambiguation).

"Cavern" redirects here. For other uses, see Cavern (disambiguation).

Lechuguilla Cave, New Mexico, USA