drift upward
71Thunderstorm — Electrical storm redirects here. For other uses, see Electrical storm (disambiguation). A typical thunderstorm A thunderstorm, also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of weather… …
72Tooth eruption — is a process in tooth development in which the teeth enter the mouth and become visible. It is currently believed that the periodontal ligaments play an important role in tooth eruption. Primary (baby) teeth erupt into the mouth from around 6… …
73Alps — /alps/, n. (used with a pl. v.) a mountain range in S Europe, extending from France through Switzerland and Italy into Austria, Slovenia, and Croatia. Highest peak, Mont Blanc, 15,781 ft. (4810 m). * * * I Mountain system, south central Europe.… …
74Islam — Islamic /is lam ik, lah mik, iz /, Islamitic /is leuh mit ik, iz /, adj. /is lahm , iz , is leuhm, iz /, n. 1. the religious faith of Muslims, based on the words and religious system founded by the prophet Muhammad and taught by the Koran, the… …
75tropical cyclone — a cyclone that originates over a tropical ocean area and can develop into the destructive storm known in the U.S. as a hurricane, in the western Pacific region as a typhoon, and elsewhere by other names. Cf. extratropical cyclone, hurricane (def …
76valley — valleylike, adj. /val ee/, n., pl. valleys. 1. an elongated depression between uplands, hills, or mountains, esp. one following the course of a stream. 2. an extensive, more or less flat, and relatively low region drained by a great river system …
77dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
78Nystagmus — Rapid rhythmic repetitious involuntary (unwilled) eye movements. Nystagmus can be horizontal, vertical or rotary. * * * Involuntary rhythmic oscillation of the eyeballs, either pendular or with a slow and fast component. [G. nystagmos, a nodding …
79List of Billboard Hot 100 chart achievements and milestones — This is a comprehensive listing which highlights significant achievements and milestones based upon Billboard magazine s singles charts, most notably …
80Mining — This article is about the extraction of geological materials from the Earth. For the municipality in Austria, see Mining, Austria. For the siege tactic, see Mining (military). For name of the Chinese emperor, see Daoguang Emperor. Simplified… …
