2021考研英语阅读限时练习题（2）

潍坊中公教育 2020-04-02 14:23:34 中公在线咨询

2020考研院校信息汇总

2011-2019年考研国家线汇总

考研英语是研究生考试科目中的一大难题，而考研英语阅读又是考研英语比较难的一部分，所以从备考初期，背诵单词之余，就要开始考研英语阅读题目的练习，中公考研小编分享“2021考研英语完形填空基础练习(2)”，希望能给备战2020考研考生提供帮助。

The stone age， The Iron Age. Entire epochs have been named for materials. So what to call the decades ahead? The choice will be tough. Welcome to the age of superstuff. Material science –– once the least sexy technology &ndash is bursting with new， practical discoveries led by superconducting ceramics that may revolutionize electronics. But superconductors are just part of the picture： from house and cars to cook pots and artificial teeth， the world will someday 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 example， 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， ice-skating 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. Besides， composites &ndash plastic reinforced with fibers of graphite or other compounds &ndash 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 cable 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 near future.

1. How many new materials are mentioned in this passage?

[A] Two

[B] Three

[C] Four

[D] Five

2. Why does the author mention genetic engineering and computer science?

[A] To compare them with the new materials.

[B] To show the significance of the new materials on the future world.

[C] To compare the new materials to them.

[D] To explain his view point.

3. Why is transition difficult?

[A] Because transition requires money and time.