#153. Does a zoo have no useful purpose?
Perhaps one of the most blameworthy factors that make some people raise the eyebrow to zoos and criticize that "A zoo has no useful purpose" is its exorbitant price to maintain. However, it is too hasty to say so, since most zoos have their significance, both educational and scientific.
Modern zoos act as centers of education and are designed to make learning about animals an interesting and enjoyable experience. They provide visitors with the chance to see rare creatures, such as tigers, zebras, penguins, and giant pandas, which come from many different parts of the globe. Zoos also introduce people to their own local wildlife, offering a valuable learning experience in an increasingly urban world. At the same time, most zoos provide educational programs aimed at a wide range of ages. A visit to a zoo provides children an opportunity to see and touch animals other than household pets. For older schoolchildren, many zoos conduct classes or day trips that focus on different aspects of animal biology and the impact of humans on animal life.
Modern zoos also have their scientific imports and can function as a sanctuary for endangered animals and therefore help maintaining ecosystems. In zoos scientists can create an animal population that can become self-sustaining in the wild. An example of a successful reintroduction to the wild is the Père David's deer. This Asian deer was native to marshlands in northeast China before its habitat was destroyed more than 800 years ago and it became extinct in the wild. Since that time the species has been bred in zoos in China and later in Europe. In 1985 four Père David' s deer were released to the wild in a protected animal reserve in China, where they are now breeding successfully.
On the other hand, some experts warn against placing too much reliance on zoos as biological "arks," where species can be protected regardless of environmental changes outside. Critics warn that zoos, like all human institutions, are vulnerable to unforeseen events, such as disease, fires, and financial or social upheaval. More significantly, the number of species that zoos can protect is strictly limited. Today's zoos are home to no more than a few thousand species— only a fraction of the world's animal life. Zoos already have to perform a delicate balancing act between large, crowd-attracting animals and threatened animals that have less visitor appeal. During the 21st century, zoo experts will face even harder decisions about which species they can afford to save.
153. 动物园毫无用处吗？
有些人对动物园竖起眉毛表示怀疑并批评“动物园没有用”，也许最应该为此受到责备的原因就是维持它的昂贵费用。然而，这样说太草率了，因为绝大多数动物园都在教育和科研方面有着重要性。
现代动物园作为教育中心，在这里学习和动物有关的知识被设计成有趣而又令人愉快的体验。它们给参观者提供了一个看到诸如老虎、斑马、企鹅和大熊猫等来自世界各地的稀有动物的机会。动物园也会向人们介绍他们本地的野生动物，提供了在一个不断城市化的世界中的珍贵的学习经验。同时，绝大多数动物园都提供针对各个年龄阶段的教育节目。去参观动物园给孩子们提供了一个观看和接触除了家养宠物之外的各种动物的机会。对于年龄大一些的学龄儿童，很多动物园安排了关于生物学的不同方面和人类对动物生活影响的课程或者全天行程。
现代动物园还有他们在科学方面的重要性，而且可以作为各种濒危动物的避难所，从而有助于维持生态系统。在动物园里科学家可以增加一种动物的数量直到它们可以自己在野外繁衍。麋鹿就是一个成功回到野生环境的例子。这个亚洲鹿种在800多年前它们的栖息地被破坏之前，曾经生活在中国东北的沼泽之中；后来它们在野外灭绝了。从那时起在中国、以及后来在欧洲，动物园里都饲养着这个物种。在1985年，四头麋鹿被放回了中国的一个动物保护区的野生环境中，如今它们在那里繁殖得很成功。
- blameworthy ［ˈbleimˌwə:ði］ adj. 该受到责备的
- self-sustaining ［ˌselfsəsˈteiniŋ］adj. 自给的
- exorbitant ［igˈzɔ:bitənt］ adj. 昂贵的
- Père David's deer 麋鹿
- penguin ［ˈpeŋgwin］ n. 企鹅
- marshland ［ˈma:ʃˌlænd］ n. 沼泽
- globe ［gləub］ n. 地球；世界
- ark ［a:k］ n. 方舟
- impact ［ˈimˌpækt］ n. 冲击；影响
- vulnerable ［ˈvʌlnərəbəl］ adj. 脆弱的
- sanctuary ［ˈsæŋktjuˌeri］ n. 避难所
- upheaval ［ʌpˈhi:vəl］ n. 剧变