【正文】 。蝙蝠這種回響定位法常拿來(lái)和原理與之很相近似的雷達(dá)相比。 98. It is impossible to say simply for the fun and exercise: as soon as the question of prestige arises, as soon as you feel that you and some larger unit will be disgraced if you lose, the most savage bative instincts are around. ：一旦有了問(wèn)題，一旦你覺(jué)得你輸了你和你所屬團(tuán)體會(huì)有失體面時(shí)，你最野蠻的好斗本能就會(huì)被激發(fā)出來(lái)。他們不是焦慮的向上爬的人，他們不會(huì)對(duì)物質(zhì)性的東西難舍難分。 96. I find young people exciting. They have an air of freedom, and they have not a dreary mitment to mean ambitions or love fort. They are not anxious social climbers, and they have no devotion to material things. 。 95. There is only one difference between an old man and a young one: the young man has a glorious future before him and old one has a splendid future behind him: and maybe that is where the rub is. ：年輕人的前面有輝煌的未來(lái)，老年人燦爛的未來(lái)卻已在它們身后。 　　94. It is true that during their explorations they often faced difficulties and dangers of the most perilous nature, equipped in a manner which would make a modern climber shudder at the thought, but they did not go out of their way to court such excitement. ，他們?cè)谔诫U(xiǎn)中遇到了極具威脅性的困難和危險(xiǎn)，而他們的裝備會(huì)讓一個(gè)現(xiàn)代登山者想一想都會(huì)渾身顫栗。 93. Insects would make it impossible for us to live in the world。 91. Arid regions in the southwestern United States have bee increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hillclimbing contests or in caving new trails in the desert. ，對(duì)越來(lái)越多擁有摩托車或越野單車類車輛的，喜歡放縱于爬坡比賽或開辟新的沙漠通道的尋歡作樂(lè)者具有不斷增長(zhǎng)的吸引力。 89. Because of the space crunch, the Art Museum has bee increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections. ，藝術(shù)博物館在考慮購(gòu)買和接受捐贈(zèng)的藝術(shù)品是越來(lái)越慎重，有些情況下放棄其進(jìn)一步改善收藏的機(jī)會(huì)。 87. Three years of research at an abandoned coal mine in Argonne, Illinois, have resulted in findings that scientists believe can help reclaim thousands of mine disposal sites that scar the coalrich regions of the United States. ，科學(xué)家們相信這些成果可以幫助改造把美國(guó)產(chǎn)煤區(qū)弄得傷痕累累的數(shù)千個(gè)舊煤場(chǎng)。它能做的最敏捷的動(dòng)作就是揮一揮它彎曲的胳膊。 85. The sloth pays such little attention to its personal hygiene that green algae grow on its coarse hair and munities of a parasitic moth live in the depths of its coat producing caterpillars which graze on its mouldy hair. Its muscles are such that it is quits incapable of moving at a speed of over a kilometer an hour even over the shortest distances and the swiftest movement it can make is a sweep of its hooked arm. ，以至于它粗糙的毛發(fā)上生出綠苔，成群的寄生蛾生長(zhǎng)在它的皮毛深處，變成毛毛蟲，并以它的臟毛為食。他在那里正式任職長(zhǎng)達(dá)整整一代人的時(shí)間。 83. Even more shocking is the fact that the number and rate of imprisonment have more than doubled over the past twenty years, and recidivismthat is the rate for rearrestis more than 60 percent. ，以及累犯率——即再次拘押的比例——為百分之六十強(qiáng)。 82. Television is more than just an electronics。 80. Since the consumer considers the best fruit to be that which is the most attractive, the grower must provide products that satisfy the discerning eye. ，所以種植者必須提供能滿足挑剔眼光的產(chǎn)品。 78. As a result of what is now know in physics and chemistry, scientists have been able to make important discoveries in biology and medicine. 。 76. The beaver chews down trees to get food and material with which to build its home. ，以便取食物并獲得造窩的材料。 74. When Henry Ford first sought financial backing for making cars, the very notion of farmers and clerks owning automobiles was considered ridiculous. ，農(nóng)民和一般職員也能擁有汽車的想法被認(rèn)為是可笑的。 72. Often very annoying weeds, goldenrods crowd out less hardy plants and act as hosts to many insect pests. ，它擠走不那么頑強(qiáng)的植物，并找來(lái)很多害蟲。 70. Even though the precise qualities of hero in literary words may vary over time, the basic exemplary function of t