A、They developed very slowly. B、They prohibited downloading music. C、They stopped tapes from circulating. D、They slowed down tec

Very rapidly, 3D printers have spread from scientific labs to industrial workshops to private homes. The range of available machines is on display at 3D print shows, like the one held last November in London, from sophisticated models that can print complex objects, such as replicas of human organs, to more affordable machines that make children’s toys or parts for home appliances.(22)A German firm recently displayed a prototype of a car chassis(汽车底盘)printed in one piece, while a Chinese manufacturer advertised a house created in a 3D printer.
    With the help of a computer, practically anyone can print exact copies of a variety of objects, and potentially violate the law. Julie Samuels, a lawyer from the Electronic Frontier Foundation, says,(23)"If a certain design that you want to print is covered by copyright, then you print that, and you are fringing someone’s copyright."
     (24)Several decades ago, legislatures and the music industry were equally slow to adjust when suddenly anyone could copy music, first to magnetic tapes and now electronic media. But just as in the music industry, the founder of the website 3DPlus.me, Cydni Tetro. says she expects to see 3D licenses very soon. "All of those companies are in very active engagements right now about how they’ll deploy 3D printed products over the next year, and we’re going to see that."(25)3D printer designer Diego Porqueras says owners of 3D printers and copyright owners should come to terms. The lack of legislation related to 3D printing will hardly stop the technology from spreading, but experts say they hope the new laws will not punish people for printing a copy of something for their personal use.
22. What are on displays in the 3D print shows of a German company?
23. What kind of action might relate to infringing copyright according to the lawyer?
24. What do we know about the laws on music duplication decades ago?
25. What does the 3D printer designer Diego Porqueras advise to do?