When an invention is made, the inventor has three possible (1) of action open to him: he can give the invention to the world by publishing it, keep the idea (2) , or patent it.
A (3) patent is the result of a bargain (4) between an inventor and the state, hut the inventor gets a limited period of monopoly and publishes full details of his invention to the public after that period (5) .
Only in the most exceptional circumstances (6) the lifespan of a patent (7) to alter this normal process of events.
The longest extension ever (8) was to Georges Valensi; his 1939 patent for color TV receiver circuit was extended until 1971 because for most of the patent’s normal life there was no color TV to (9) and thus no hope for reward for the invention.
Because a patent remains permanently (10) after it has terminated, the shelves of the library attached to the (11) office contain details of literally millions of ideas that are free for anyone to use and, if (12) than half a century, sometimes even repatent. Indeed, patent experts often advise anyone (13) to avoid the high cost of conducting a search through (14) patents that the one sure way of violation of any other inventor’s right is to plagiarize a dead patent. Likewise, because publication of an idea in any other form (15) invalidates further patents on that idea, it is traditionally (16) to take ideas from other areas of print. Much modern technological advance is (17) on these presumptions of legal security.
Anyone closely (8) in patents and inventions soon learns that most "new" ideas are, in fact, as old as the hills. It is theft reduction to commercial practice, either through necessity or dedication, or through the availability of new technology, (19) makes news and money. The basic patent for the theory for magnetic recording dates back to 1886. Many of the original ideas behind television originate (20) the late 19th and early 20th century. Even the Volkswagen rear engine ear was anticipated by a 1904 patent for a cart with the horse at the rear.
20（）
A.with
B.off
C.before
D.from
某七层商店一住宅采用框支墙梁结构和现浇混凝土楼（屋）盖，抗震等级二级，2层至7层为住宅。底层框支柱截面400mm×400mm，框支托梁b×h＝300mm×650mm，均采用C30混凝土，纵向受力钢筋采用HRB335级、箍筋采用HPB300级。承重砌体墙体采用MU10烧结普通砖，底层和墙梁计算高度范围内墙体采用M10混合砂浆，其他采用M5混合砂浆，砌体施工质量控制等级为B级。其一榀横向框支墙梁在重力荷载代表值作用下的计算简图如图1-12（a）所示，该榀框支墙梁
轴在Q、F作用下的框架内力如图1-12（b）所示；在Q作用下的框架内力如图1-12（c）所示。已知框支墙梁底层水平地震剪力标准值
，其作用下的弯矩如图1-12（d）所示。提示：按《建筑抗震设计规范》（GB50011-2010）和《砌体结构设计规范》（GB50003-2011）作答。