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1、 2022年职称英语考试完型填空习题(九)Spider webs are more than homes, and they are ingenious traps. And the worlds best web spinner may be the Golden Orb Weaver spider. The female Orb Weaver spins a web of fibers thin enough to be invisible to insect prey, yet _1_ enough to snare a flying bird without breaking. The
2、 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_ t
3、o 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 years. The silky thread is five times stronger than steel by weight and absorbs the force of an impact three times better than Kevla
4、r, 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
5、 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 run. Think parachute cords and suspension bridge cables. A steady _10_ of spider silk would be worth billions of dollars but how to prod
6、uce 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 Golden Orb dragline. The _12_ step: extract silk-making genes from the spi
7、ders. 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
8、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. wool3. A. repair B. pull C. move D. weave4. A. him B. her C. it D. those5. A. refixes B. reproduces C. remakes D. reuses6. A. metal
9、B. mass C. material D. model7. A. bredth B. length C. height D. strength8. A. close B. well C. open D. awake9. A. hurry B. worry C. wonder D. use10. A. shipment B. supply C. run D. exchange11. A. run B. go C. deal D. work12. A. previous B. foremost C. first D. front13. A. milk B. meat C. lungs D. muscle14. A. no B. any C. some D. many15. A. As fast as B. as gently as C. as fully as D. as little as
