99. It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles——or locate flying insects on which they feed. This echo-location in bats is often compared with radar, the principle of which is similar.
99.人們已經發現，某些蝙蝠發出尖叫聲並靠接受迴響來鎖定和避免障礙物——或者找到它們賴以為生的昆蟲。蝙蝠這種迴響定位法常拿來和原理與之很相近似的雷達相比。
certain
97. I am always amazed when I hear people saying that sport creates goodwill between the nations, and that if only the common peoples of the world could meet one another at football or cricket, they would have no inclination to meet on the battlefield.
97 .每次我聽說體育運動能夠在國家間建立起友好感情，說世界各地的普通人只要能在足球場或板球場上相遇就會沒有興趣在戰場上相遇的話，我都倍感詫異。
amazed
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.
95.老人和年輕人之間只有一個區別：年輕人的前面有輝煌的未來，老年人燦爛的未來卻已在它們身後。這也許就是困難之所在。
difference
93. Insects would make it impossible for us to live in the world; they would devour all our crops and kill our flocks and herds, if it were not for the protection we get from insect-eating animals.
93.昆蟲就將會使我們無法在這個世界上居住；如果我們沒有受到以昆蟲為食的動物的保護，昆蟲就會吞嚼掉我們所有的莊稼並殺死我們飼養的禽獸。
impossible
91. Arid regions in the southwestern United States have become increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hill-climbing contests or in caving new trails in the desert.
91.美國西部的不毛之地正成為玩耍的地方，對越來越多擁有摩托車或越野單車類車輛的，喜歡放縱於爬坡比賽或開闢新的沙漠通道的尋歡作樂者俱有不斷增長的吸引力。
region
89. Because of the space crunch, the Art Museum has become increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections.
89.由於空間不足，藝術博物館在考慮購買和接受捐贈的藝術品是越來越慎重，有些情況下放棄其進一步改善收藏的機會。
space
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 coal-rich regions of the United States.
87.在伊利諾州Argonne市的一個廢棄煤礦的三年研究取得了成果，科學家們相信這些成果可以幫助改造把美國產煤區弄得傷痕累累的數千個舊煤場。
abandoned
85. The sloth pays such little attention to its personal hygiene that green algae grow on its coarse hair and communities of a parasitic moth live in the depths of its coat producing caterpillars which graze on its dirty 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.
85.樹獺即不講究衛生，以至於它粗糙的毛髮上生出綠苔，成群的寄生蛾生長在它的皮毛深處，變成毛毛蟲，並以它的髒毛為食。她的肌肉不能讓他哪怕在很短的距離以內以每小時一公里的速度移動。它能做的最敏捷的動作就是揮一揮它彎曲的胳膊。
sloth
82. Television is more than just electronics; it is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.
82.電視不僅僅是一件電器；它是表達的手段和交流的載體並因此成為聯繫他人的有力工具。
electronics
79. The practice of making excellent films based on rather obscure novels has been going on so long in the United States as to constitute a tradition.
79.根據默默無聞的小說製作優秀影片在美國由來已久，已經成為傳統。
excellent
76. The beaver chews down trees to get food and material with which to build its home.
76.水獺啃倒樹木，以便取食物並獲得造窩的材料。
chew
73. Starting around 7000 BC, and for the next four thousand years, much of the Northern Hemisphere experienced temperatures warmer than
at present.
73.大約從公元前七千年開始，在四千年當中，北半球的溫度比現在高。
around
70. Even though the precise qualities of hero in literary words may vary over time, the basic exemplary function of the hero seems to remain constant.
70.歷代文學作品中的英雄本色雖各有千秋，但其昭世功力卻是恆古不變的。
precise
67. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible.
67.科學家不知道恐龍為何絕種了，但是一些理論推斷是地理，氣候和海平面的變化造成的。
dinosaur
64. The pigmentation of a pearl is influenced by the type of oyster in which it develops and by the depth, temperature, and the salt content of the water in which the oyster lives.
64.珍珠的色澤受到作為其母體牡蠣種類及牡蠣生活水域的深度，溫度和含鹽度的製約。
pigmentation
Difficult circumstances serve as a textbook of life for people.困難坎坷是人們的生活教科書
personal management 人事管理
casual leave 例假；事假
61. Buyers and sellers should be aware of new developments in technology can and does affect marketing activities.
61.購買者和銷售者都應該留意技術的新發展，原因很簡單，因為技術能夠並且已經影響著行銷活動。
aware
adj.
58. Among almost seven hundred species of bamboo, some are fully grown at less than a foot high, while others can grow three feet in twenty-four hours.
58.在竹子的近七百個品種中，有的全長成還不到一英尺，有的卻能在二十四小時內長出三英尺。
among
55. The history of painting is a fascinating chain of events that probably began with the very first pictures ever made.
55.優化歷史是由一連串的迷人事件組成，其源頭大概可以上溯到最早的圖畫。
history
n.
52. Anarchism is a term describing a cluster of doctrines and attitudes whose principal uniting feature is the belief that government is both harmful and unnecessary.
52.無政府主義這個詞描述的是一堆理論和態度，它們的主要共同點在於相信政府是有害的，沒有必要的。
describe
vt.
