Wonder Webs
Spider webs are more than homes, and they are ingenious traps. And the worlds best web spinner may be the Goldern Orb Weaver spider. The female Orb Weaver spins a web of fibers thin enough to be invisible to insect prt, yet _____1____ enough to snare a flying bird without breaking.
The secret of the webs strength? A type of super-resilient ____2____ called dragline. When the female spider is ready to ____3_____ the webs spokes and frame, she uses her legs to draw the airy thread out through a hollow nozzle in her belly. Dragline is not sticky, so the spider can race back and forth along ____4___ to spin the webs trademark spiral.
Unlike some spiders that weave a new web every day, a Golden Orb Weaver _____5_____ her handiwork until it falls apart, sometimes not for two years1. The silky thread is five times stronger than steel by weight and absorbs the force of an impact three times better than Kevlar, a high-strength human-made ____6____ used in bullet-proof vests. And thanks to its high tensile strength, or the ability to resist breaking under the pulling force called tension, a single strand can stretch up to 40 percent longer than its original _____7____ and snap back as well as new. No human-made fiber even comes ____8____.
It is no ____9____ manufacturers are clamoring for spider silk. In the consumer pipeline: high-performance fabrics for athletes and stockings that never run2. Think parachute cords and suspension bridge cables. A steady _____10_____ of spider silk would be worth billions of dollarsbut how to produce it? Harvesting silk on spider farms does not ____11_____ because the territorial arthropods have a tendency to devour their neighbors.
Now, scientists at the biotechnology company Nexia are spinning artificial silk modeled after Goldern Orb dragline. The ____12____ step: extract silk-making genes from the spiders. Next, implant the genes into goat egg cells. The nanny goats that grow from the eggs secrete dragline silk proteins in their ______13____ . The young goats pass on the silk-making gene without____14____ help from us, says Nexia president Jeffrey Turner. Nexia is still perfecting the spinning process, but they hope artificial spider silk will soon be snagging customers ____15____ the real thing snags bugs.
1. A) tough B) soft C) large D) smooth
2. A) cloth B) silk C) nylon D) wool
3. A) repair B) pull C) move D) weave
4. A) him B) her C) it D) those
5. A) refixes B) reproduces C) remakes D) reuses
6. A) metal B) mass C) material D) model
7. A) bredth B) length C) height D) strength
8. A) close B) well C) open D) awake
9. A) hurry B) worry C) wonder D) use
10. A) shipment B) supply C) run D) exchange
11. A) run B) go C) deal D) work
12. A) previous B) foremost C) first D) front
13. A) milk B) meat C) lungs D) muscle
14. A) no B) any C) some D) many
15. A) as fast as B) as gently as C) as fully as D) as little as
参考答案:ABDCD CBACB DCABA
职称英语考试如何选词典及如何用词典
掌握三大利器职称英语等级考试必过
职称英语考试利用零散时间巧复习
职称英语提醒考场答题顺序及时间控制
学好职称英语十条经验总结
英语菜鸟不背单词通过职称英语
职称英语等级考试寒假期间备考技巧
2013年全国职称英语等级考试顺利通关五步走
职称英语考试阅读理解题必备高分秘笈
职称英语考试考试技巧如何查字典
职称英语考试语法突破的七步曲
职称英语考试词汇题解题方法
2014年职称英语考试考前20天冲刺精选答疑
职称英语考试临考前需注意六大误区
顺利通过职称英语考试的关键是扩大阅读范围
2013年职称英语考试强化阶段两大复习重点
学好三大致胜法则顺利通过职称英语考试
职称英语考试考前如何调整心态
职称英语考试补全短文解题技巧
职称英语考前一个月冲刺复习要点
职称英语考试考前需要注意7大事项
职称英语制胜宝典必备词典
职称英语考试复习日程安排表
职称英语考试考场中阅读文章4大方法
职称英语技巧学会在阅读句子中背诵单词
职称英语备考在阅读句子中记忆单词
职称英语考试考前复习抓住九大要点
职称英语考试方法阅读理解例证题型攻略
综合类职称英语考试得分技巧
拿到职称英语考试教材后的复习步骤
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |