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  3. The Stone age, the Iron age. Entire epochs have been named for materials. So what to name the decades ahead? The choice will be

The Stone age, the Iron age. Entire epochs have been named for materials. So what to name the decades ahead? The choice will be

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问题     The Stone age, the Iron age. Entire epochs have been named for materials. So what to name the decades ahead? The choice will be tough. Welcome to the age of superstuff. Material science—once the least sexy technology—is bursting with new, practical discoveries led by superconducting ceramics that may revolutionize electronics. But superconductors are just part of the picture; from houses and cars to cook pots and artificial teeth, the world will sometime be made of different stuff. Exotic plastics, glass and ceramics will shape the future just as surely as have genetic engineering and computer science.
    The key to the new materials is researchers’ increasing ability to manipulate substances at the molecular level. Ceramics, for instance, have long been limited by their brittleness. But by minimizing the microscopic imperfections that cause it, scientists are making far stronger ceramics that still retain such qualities as hardness and heat resistance. Ford Motor Co. now uses ceramic tools to cut steel. A firm called Kyocera has created a line of ceramic scissors and knives that stay sharp for years and never rust or corrode.
    A similar transformation has overtaken plastics. High-strength polymers now form bridges, iceskating rinks and helicopter rotors. And one new plastic that generates electricity when vibrated or pushed is used in electric guitars, touch sensors for robot hands and karate jackets that automatically record each punch and chop. Even plastic litter, which once threatened to permanently blot the landscape, has proved amenable to molecular tinkering. Several manufacturers now make biodegradable forms; some plastic six-pack rings for example, gradually decompose when exposed to sunlight. Researchers are developing ways to make plastics as recyclable as metal or glass. What’s more, composites—plastic reinforced with fibres of graphite or other compounds—made the round-the-world flight of the voyager possible and have even been proved in combat:a helmet saved an infantryman’s life by deflecting two bullets in the Grenada invasion.
    Some advanced materials are old standard with a new twist. The newest fiberoptic cables that carry telephone calls cross-country are made of glass so transparent that a piece of 100 miles thick is clearer than a standard window pane.
    But new materials have no impact until they are made into products. And that transition could prove difficult, for switching requires lengthy research and investment. It can be said a firmer handle on how to move to commercialization will determine the success or failure of a country in the coming future.
Why could not ceramics be used widely in the past?
选项 A、Because of their brittleness.
B、Because people didn’t know how to use them.
C、Because they were not useful.
D、Because they could not resist heat.
答案A
解析 由短文第二段中的“Ceramics，flor instance，have long been limited by their brittleness．”。
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