parallel-sided plate
21China — /chuy neuh/, n. 1. People s Republic of, a country in E Asia. 1,221,591,778; 3,691,502 sq. mi. (9,560,990 sq. km). Cap.: Beijing. 2. Republic of. Also called Nationalist China. a republic consisting mainly of the island of Taiwan off the SE coast …
22optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …
23Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
24Printed circuit board — Part of a 1983 Sinclair ZX Spectrum computer board; a populated PCB, showing the conductive traces, vias (the through hole paths to the other surface), and some mounted electrical components A printed circuit board, or PCB, is used to… …
25Baseball field — The baseball diamond of the San Diego Padres PETCO Park, seen from the stands. A baseball field, also called a ball field or a baseball diamond, is the field upon which the game of baseball is played. The terms baseball field and ball field are… …
26building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… …
27Inner German border — Innerdeutsche Grenze North and central Germany …
28Rhinoplasty — For the album by Primus, see Rhinoplasty (album). Rhinoplasty Intervention Rhinoplasty: The lower lateral cartilage (greater alar cartilage) exposed for plastic modification via the left nostril …
29rock — rock1 rockless, adj. rocklike, adj. /rok/, n. 1. a large mass of stone forming a hill, cliff, promontory, or the like. 2. Geol. a. mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or considerable… …
30Rock — /rok/, n. a male given name. * * * I In geology, a naturally occurring and coherent aggregate of minerals. The three major classes of rock igneous, sedimentary, and metamorphic are based on the processes that formed them. These three classes are… …
