FILTON, just outside Bristol, is where Britain’s fleet of Concorde supersonic（超音速的）airliners was built. There, something remarkable is being created. Little by little a machine is “printing” a complex titanium bracket (钛合金支架), about the size of a shoe, which normally would have to be cut from a solid block of metal. Brackets are only the beginning. The researchers at Filton have a much bigger ambition: to print the entire wing of an airliner.
Unrealistic as this may seem, many other people are using 3D printing technology to create similarly remarkable things. These include medical implants, jewellery, football boots designed for individual feet, lampshades, racing-car parts, solid-state batteries and customized mobile phones. Some are even making mechanical devices (仪器). At the Massachusetts Institute of Technology (MIT), Peter Schmitt, a PhD student, has been printing something that is like the workings of a grandfather clock. It took him a few attempts to get right, but eventually he removed the plastic clock from a 3D printer, hung it on the wall and pulled down the counterweight. It started ticking.
Engineers and designers have been using 3D printers for more than a decade, but mostly to make original types quickly and cheaply before they embark on the expensive business of tooling up a factory to produce the real thing. As 3D printers have become more able to work with a broader range of materials, including production-grade plastics and metals, the machines are increasingly being used to make final products too. More than 20% of the output of 3D printers is now final products rather than original types, according to Terry Wohlers, who runs a research firm specializing in the field. He predicts that this will rise to 50% by 2020.
1. Which of the following is true according to the passage?
A. Filton is in the centre of Bristol.
B. Peter tried to print a clock, but in vain.
C. a remarkable metal bracket is being created.
D. 3D printing technology is available to all of us.
2. The underlined word “embark” probably means “_________”.
A. work B. land C. depend D. fix
3. We can conclude from the last paragraph that __________.
A. Terry Wohlers’ s firm will make great profits
B. the technology of 3D printers will be widely adopted
C. 3D printers have been in use for at least 100 years
D. engineers and designers prefer printing original products
4. The passage is developed mainly in the form of _______.
A. time and events B. definition and description
C. contrast and conclusion D. examples and statements