問題詳情

[B]
(A) radiate
(B) with which
(C) intercept
(D) in place
(E) length(AB) withstand (AC) range (AD) that (AE) ordered (BC) windingSpider webs are one of the most fascinatingexamples of animal architecture. The most beautiful_51__ are the orb webs. The mainfunction of the web is to __52__ and hold flyingprey, such as flies, bees and other insects, longenough for the spider to catch them. In order to doso, the threads of the web have to __53__ the impactforces from large and heavy prey as well asenvironmental forces from wind and rain for at leasta day in most cases.The orb web is found to have two main characteristics. The first is its geometry, whichcomprises an outer frame and a central part from which threads __54__ outward. Enclosedin the frame are capture spirals __55__ round and round from the web center out to theframe. The whole web is in tension and held __56__ by anchor threads, which connect theframe to the surrounding vegetation or objects. The second and perhaps most importantcharacteristic is the material __57__ it is built. Spider silk is a kind of natural composite thatgives this lightweight fiber a tensile strength comparable to __58__ of steel, while at thesame time making it very elastic. Two types of silk threads are used in the web. One ishighly elastic and can stretch to almost twice its original __59__ before breaking and, formost types of spiders, is covered in glue. This type is used in the capture spiral for catchingand holding prey. The other is stiffer and stronger, and is used for the radius, frames andanchor threads, which allows the web to sustain prey impact and to keep its structuralstrength through a wide __60__ of environmental conditions.
51

參考答案

答案：A,E
難度：非常困難0
統計：A(3),B(6),C(0),D(0),E(0)

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