例題4
　　A Dog's Dilemma
　　Para 1 Finding a babysitter (尋找一個看護小孩的人)while you go out to work is, for example, an inconvenience(很不方便). For the African wild dog, one of the continent's most endangered carnivores(第一題：最有滅絕危險的食肉動物之一), it's a matter of life and death(生死攸關的事情). New research shows that once packs fall below a certain size(一旦動物群的數(shù)目低于某一規(guī)模), there are not enough animals to both hunt food and stay at home protecting the young.(就沒有足夠的動物既去捕獵又留在家里看護幼崽。)
　　Para 2 The African wild dog(非洲野狗) has declined drastically over the past century. Habitual loss(regular; usual 慣常的; 通常的;損失), persecution(受到殘害) and unexplained outbreaks of disease(莫名其妙的疾病的爆發(fā)) have all been blamed(是其中的原因). Only 3,000 to 5,000 animals remain, and the species is expected to go extinct (滅絕)within decades if the trend continues. (第一題：非洲野狗的數(shù)量急劇下降，在未來幾十年可能滅絕。)
　　Para 3 Other large carnivores such as the spotted hyena face similar pressures, yet are not declining. (第二題：面臨類似的物種生存壓力，但是數(shù)量卻沒有下降)Now Franck Courchamp of Cambridge University has found a reason why. The dog's weakness (狗的弱點在于它的社會組織)lies in its social organisation.
　　Para 4 Within each pack(狗群) of up to 20 adults and pups(大狗小狗), only the dominant male and female breed. The remaining animals help raise the pups(幫助養(yǎng)小狗), cooperating to hunt prey (捕獵)and defend the kill (保護狗群不受其他食肉動物的傷害)from other carnivores.
　　Para 5 Because pups can't keep up on a hunt, large packs leave an adult (第四題：文章確實說狗群會留下一位成年狗來看護小狗，但并沒有說總會留下一位具有支配作用的母狗來看護幼崽，所以，第四題選擇“B: Wrong”。)behind to protect them from predators, which include lions and hyenas.(第三題：文章第五段確實提到了獅子，但是這里并沒說獅子在幾十年后會消亡。所以，文章中沒有提到，選擇C。) But leaving a babysitter also carries costs. A smaller hunting party (較小的狩獵群體) is less able to tackle large prey (對付大的獵物)and to defend the kill1.(第五題：看護小狗與獵食是不能統(tǒng)一的。所以，第五題選擇“A：Right”。) There is also one less stomach in which to carry food back to the den(野獸的洞穴), and one more mouth to feed when they get there.
　　Para 6 Courchamp investigated this awkward trade-off (尷尬的兩難境地)by modeling (模擬) how the costs of a babysitter change with decreasing pack size.(隨著狗群的減小，看護幼崽的情況會發(fā)生什么樣的變化。)This showed that packs of more than five adults (五個成年狗組成的一個狗群能夠養(yǎng)活所有幼崽，并騰出一只成年狗在家里看護小狗)should be able to feed all the pups and still spare a babysitter. (但是，狗群成年狗數(shù)目不足五只的情況下，這對捕獵和看護小狗都是有影響的，兩者都會受到損失。要不然，這些狗就得增加外出捕獵的次數(shù)作為彌補——這本身就需要狗群付出代價。)But with smaller packs, either the hunting or the babysitting suffers, or the animals have to compensate by increasing the number of hunting excursions -- which itself carries a cost (代價)to the pack(狗群). (第六題：這段話表明，狗群規(guī)模的大小對于它們的生存是至關重要的。每個狗群數(shù)目低于5只成年狗的話，就很被動。所以，第六題選擇“A：Right”。)
　　Para 7 Field observations in Zimbabwe supported the model. Packs of five animals or fewer left pups unguarded more frequently than larger packs did. There was also evidence that when they did leave a babysitter, they were forced to hunt more often.
　　Para 8 A pack which drops below a critical size becomes caught in a vicious circle, says Courchamp2, (第六題：一個群體的規(guī)模降到警戒線以下時就會陷入惡性循環(huán)。)who is now at Paris-Sud University. "Poor reproduction and low survival further reduces pack size, culminating in failure of the whole pack." And deaths caused by human activity, says Courchamp, may be what reduces pack numbers to below the sustainable threshold. Mammal ecologist Chris Carbone at London's Institute of Zoology agrees. Maintaining the integrity of wild dog packs will be vital in preserving the species, he says.(第七題：他說保持非洲野狗群的完整對保護該物種是重要的。但文章沒有說將采取何種措施保護非洲野狗。)
　　詞匯：
　　carnivore n.食肉動物 hyena n.鬣狗
　　pup n.小狗 prey n.被捕食的動物
　　predator n.捕食者 culminate n.告終;達到頂點
　　integrity n.完整 Zimbabwe n.津巴布韋
　　注釋：
　　1. A smaller hunting party is less able to tackle large prey and to defend the kill. :一個較小的捕獵群體不太容易捕捉大動物，也不太容易保衛(wèi)獵獲物。
　　2. A pack which drops below a critical size becomes caught in a vicious circle, says Courchamp.
　　Courchamp說，一個群體的規(guī)模降到警戒線以下時就會陷入惡性循環(huán)。