WATER: Chemical compound of oxygen and hydrogen, and one of the few substances to be found commonly in each of the three states of matter, solid (ice), liquid and gaseous (clouds and steam). The centigrade temperature scale is based upon its freezing point (o°) and boiling. Point (100°).
BICYCLE: Lightweight vehicle with two wheels, and tractive power supplied by the rider. There is also the tricycle with three wheels, and the tandem designed for two riders.
The Aztec civilization flourished between ad 1200 and 1550. The people were descended from an Indian tribe, the Tenochcas.
Small stars have a mass of up to about one and a half times that of the sun. They begin to form when a region of higher density in a nebula condenses into a huge globule of gas and duel that contracts under its own gravity.
Organized sound, traditionally considered to consist of three basic ingredients, used separately or in combination: rhythm, melody and harmony.
