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  3. How are jigsaw puzzles made? The method of making a jigs

How are jigsaw puzzles made? The method of making a jigs

游客2023-12-18  48
问题                      How are jigsaw puzzles made?
   The method of making a jigsaw puzzle hasn’t changed much since its invention in the late 18th century: an image is mounted on solid material and cut into a bunch of pieces. The first puzzles were made of wood and cut with a jigsaw, hence the name of the game.
   You can still buy puzzles made Of wood, but the type you’re probably most familiar with is die-cut cardboard. The die-cut press, in wide use in the United States by the 1930s, according to puzzle historian Anne D. Williams, exerts 500 tons of pressure to hold a board in place while a steel-rule die cuts it into pieces. The die consists of pieces of metal that have been shaped to form each piece in the puzzle — much like a cookie cutter punches out a shape in dough. Recent innovations include the use of lasers and computer-contro11ed water jets to cut puzzle pieces.
   Some manufacturers still have their puzzle pieces drawn by hand; others use a computer to ensure that only two pieces will fit together exactly. Puzzle styles have evolved, however, from maps and flat images to three-dimensional objects and trick puzzles. In some of these complicated puzzles, several pieces will fit together securely, but only one combination of pieces yields the correct solution to the puzzle. [br] When was the jigsaw puzzle first invented?
选项 A、Not earlier than 1800.
B、1930’s.
C、1750 to 1799.
D、Not known.
答案 C
解析
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