SEE a cell phone cover that you like on ? Forget about placing an order, paying the bill online and waiting for days for it to be delivered to you. In the near future, you'll be able to get it in minutes just by hit­ting 'print' on your computer.
You might find it hard to believe that you could actually 'print' an object like you would a picture.But it is not that hard to under­stand how it would work. Just as a traditional printer sprays (喷) ink onto paper line by line, modern 3-D printers spread material onto a suce layer by layer, from the bottom to the top, gradually building up a shape.
Instead of ink, the materials the 3-D printer uses are mainly plastic, resin (树脂)and certain metals. The thinner each layer is --- from a millimeter to less than the width of a hair --- the smoother and finer the object will be.
This may sound like a completely new technology, but the truth is that 3-D printing has been around since the late 1980s. Back then, it was barely affordable for most people, so few knew about it.
Last year, though, saw a big change in the 3-D printing industry--- printers became much cheaper. For example, 10 years ago a desktop 3-D printer might have cost £20,000 (200,000 yuan), while now they cost only about £ 1,000, according to the BBC.
Taken out of the factory and in­troduced to more diverse and com­mon uses, 3-D printing can create just about anything you can think of ---flutes (笛子), bikinis, jewelry, aircraft parts and even human organs. In fact, scientists from Cornell Univer­sity in New York have just made an artificial ear using a 3-D printer, accord­ing to Science Daily. The fake ear looks and acts exactly like a natural one.
However, as 3-D printing becomes more commonplace, it may bring about certain problems --- such as piracy. 'Once you can download a coffee maker, or print out a new set of kitchen utensils (餐具) on your personal 3-D printer, who will visit a retail (零售的) store again?' an expert in 3-D printing told Forbes News. Even more frightening, what if anyone in the world could use a 3-D printer to print out a fully functioning gun?
小题1:According to the article, in the future, the 3-D printing technology will ___.A．enable people to make better purchases onlineB．be applied as widely in our daily lives as computersC．change the way we make many productsD．shorten the time it takes for people to get what they buy online小题2:What was the big happening in the 3-D printing industry last year?A．The 3-D printing technology was taken out ofthe factory.B．The 3-D printer became more affordable forconsumers.C．The 3-D printer was used for medical treatmentfor the first time.D．3-D printing technology began to be used invarious fields.小题3:How is the last paragraph developed?A．By yzing a cause and an effect.B．By comparisons.C．By giving examples.D．By presenting research findings.小题4:What is the best title of the passage?A．Printing out everythingB．Technology in the futureC．Online shopping disappearingD．Great demand for 3-D printers