课文背诵段落

Unit 1

The lecture system ultimately harms professors as well. It reduces feedback to a minimum, so that the lecturer can neither judge how well students understand the material nor benefit from their questions or comments. Questions that require the speaker to clarify obscure points and comments that challenge sloppily constructed arguments are indispensable to scholarship. Without them, the liveliest mind can atrophy. Undergraduates may not be able to make telling contributions very often, but lecturing i nsulates a professor even from the beginner’s naïve question that could have triggered a fruitful line of thought.

讲课制度最终也会危害到教授们。反馈减少到了最低点，因此讲课者既不能判断学生对材料的了解程度，也不能受益于学生的提问或评论。学生要求说话者澄清模糊论点所提出的问题，以及挑战结构松散的论据的评论，这对于学术是必不可少的。没有这些，最活跃的头脑也会萎缩。大学生也许还不能够常常做出显著的贡献，但是讲课把教授同新生天真的问题阻隔开了，而这些问题很可能会引起一系列思考。

Smaller classes in which students are required to involve themselves in discussion put an end to students’ passivity. Students become actively involved when forced to question their own ideas as well as their instruc tor’s. their listening skills improve dramatically in the excitement of intellectual give-and-take with their instructors and yellow students. Such interchanges help professors do their job better because they allow them to discover who knows what—before final exams, not after. When exams are given in this type of course, they can require analysis and synthesis from the students, not empty memorization. Classes like this require energy, imagination, and commitment from professors, all of which can be exhausting. But they compel students to share responsibility for their own intellectual growth.

如果班级较小又要求学生参加讨论，这就会消除学生的被动性。学生被迫对他们自己和老师的思想表示怀疑时，他们就变得主动参与了。他们听的技巧在与老师和同学的学术交流所带来的刺激中大大得到提高。这种交替互动能够帮助教师做得更好，因为他们会发现谁知道什么---在期末考试前，而不是之后。这种形式的课程考试要求学生分析和综合，而不是空洞的记忆。这样的课程需要教授们的活力、想象力和投入，所有这些都会令人精疲力竭的。但是，这也使得学生为他们自己的学术成长分担责任。

Unit 2

For me, moving and staying at home, traveling and arriving, are all of a piece. The world is full of homes in which I have lived for a day, a month, a year, or, much longer. How much I care about a home is not measured by the length of time I have there. One night in a room with a leaping fire may mean more to me than many months in a room without a fireplace, a room in which my life has been paced less excitingly.

对我来说，搬家和呆在家里，旅行和到达某处是一样的。世界各地都是我的家，可能我住过一天，一个月，一年或更长时间。我在一个家居住的时间长短并不是衡量我是否喜欢它的标准。在一个有跳跃火苗的房间里仅住一晚带给我的意义也许远远大于在一个没有壁炉的房间里生活数月，因为在这样的房间里我的生活节奏会缺少一些刺激。

Taken altogether, the things that mattered a great deal to me when I was a child are very few when I compare them to the overloaded tables and overcrowded shelves through which children today have to thread their way. Only if they are very fortunate will they be able to weave together into memories the ill-assorted mass of gadgets, toys, and easily forgotten objects, objects without a past or a future, and piles of snapshots that will be replaced by new, brightly colored snapshots next year.

现在的孩子书桌和书架上都堆满了东西。和他们比起来，童年时对我有意义的东西加在一起也没有几件。但是只有当他们非常幸运的时候，他们记忆中才有可能出现那些杂乱无章的小玩意、玩具、容易被人遗忘的没有过去和未来的东西和一叠叠第二年就会被更新更好看的照片所取代的照片。

Unit 3

The most common way that we endanger other species is by destroying their natural habitats. We do this when we cut down forests, clear land for crops, build towns, dam rivers, drain swamplands of water and then fill them with dirt for construction, and when we pollute the air, the water, the soil. Most species are habitat-specific; that is, they depend on the particular offerings of a specific environment, and they cannot simply move to the next province or state and adapt as we can. The greatest diversity of life-forms on our planet are found in the tropical rainforests, yet they are disappearing faster than any other habitat – at the rate of about 50 million acres (20 million hectares ) per year. The loss of the rainforest would mean the loss of most of the species that make their homes in them.

我们危及其它物种最通常的方式是毁坏他们的自然生存环境。当我们砍伐森林、开垦耕地、建造城镇、修筑水坝，为了建设房屋而排掉沼泽地里的水，填土造地；或者当我们污染空气、水、土壤的时候，我们都是在毁坏其他物种的自然生存环境。大多数物种需要特定的生存环境，也就是说它们依赖特定的环境所提供的特定的东西而生存。它们不能象我们人类一样能到另一个省或州去适应新的生活。地球上物种最多的地方是热带雨林，但是它们的消失速度比其它任何生存环境都快----每年大约5千万英亩（2千万公顷）。雨林的消失也许意味着大多数以雨林为栖息地的物种的消失。

If we turn from medicines to food sources, we find that over 50 percent of today’s global food supply consists of just three grains –wheat, rice, and corn. If climatic changes or a plant disease suddenly threatened one of these grains, many people would starve unless we could find another species to strengthen or replace it. It is dangerous to be so dependent on such a small number of species. We need to preserve a winder variety of food species..

如果我们撇开医学而转谈食物来源，我们发现，目前全球食品供应的50%以上只包括三种谷类植物----麦子、稻子和玉米。如果气候变化或植物疾病突然威胁到这些谷类植物当中的一个，那么许多人就会挨饿，除非我们能找到其它物种来加强或替换它。人类对少数物种的过于依赖是很危险的。我们需要保护广泛的