Anyone closely involved in patents and inventions soon learns that most "new" ideas are, in fact, as old as the hills. It is their reduction to commercial practice, either through necessity or dedication, or through the availability of new technology, that makes news and money. The basic patent for the theory of magnetic recording dates back to 1886. Many of the original ideas behind television originate from the late 19th and early 20th century. Even the Volkswagen rear engine car was anticipated by a 1904 patent for a cart with the horse at the rear.

　　42. Which of the following is TRUE according to the passage?

　　[A] When a patent becomes out of effect, it can be re-patented or extended if necessary.

　　[B]. It is necessary for an inventor to apply for a patent before he makes his invention public.

　　[C] A patent holder must publicize the details of his invention when its legal period is over.

　　[D] One can get all the details of a patented invention from a library attached to the patent office.

　　[答案] C

　　[解题思路]

　　本题可以采用排除法。A选项对应于文章第二段的最后一句话“Only in the most exceptional circumstances is the lifespan of a patent extended to alter this normal process of events”()，因此只有在极为特殊的情况下才可能延长专利期，因此A选项错误。B选项的表述在文章中没有提及。D选项对应于第四段的第一句话“Because a patent remains permanently public after it has terminated, the shelves of the library attached to the patent office contain details of literally millions of ideas that are free for anyone to use and, if older than half a century, sometimes even re-patent”(因为一项专利到期后，该专利就永久公开了，因此，专利局的图书馆书架上那数百万个观点只要是超过半个世纪，任何人都可自由使用，有时甚至可以重新取得专利)，但是原文没有提到是否可以得到关于任何发明的所有细节，因此该选项也可以排除。而C选项对应于文章第二段第一句话“A granted patent is the result of a bargain struck between an inventor and the state, by which the inventor gets a limited period of monopoly (垄断) and publishes full details of his invention to the public after that period terminates”(专利的授予是发明者和国家之间形成的一种契约。根据这种契约，发明者对自己的发明可获得一定时期的垄断权，垄断期结束后，就要把该项发明的全部细节公布于众)，选项表述符合原句，是正确答案。