题文

阅读理解。

A prairie is a type of grassland. Prairies are made up of a complete interdependent ecosystem. This means that all kinds of plants and animals in a prairie region depend on one another for survival (生存). The members of a prairie ecosystem include grasses, flowering plants, animals, soil (土壤), sand, and fire.      You may look at a prairie and think there's nothing there but grass, but that' s not true. Most of the prairie's living things are below the ground. Underneath the prairie' s surface are roots and bulbs (根茎). The roots of the prairie flowers and grasses run deep. Some of them are as deep as 3.5 metres below the ground.      It is impmtant for the roots to run deep because fires are a part of the prairie ecosystem. When a fire bums through the prairie, plants with shallow (not deep) roots can not survive. Plants that have deep root systems are able to survive the fires. When fire burns across a prairre, it bums dead plants from the top and returns those nutrients (养料) to the soil. This adds to the richness of the prairie soil. Prairies have some of the richest soil in the United States. This cycle of growth and buming has been going on for thousands of years. Big bluestem is the plant that gives parts of the prairie the name "tallgrass prairie".      Big bluestem has very deep roots, and its stems (茎) are often 2 metres tall.      The American bison (野牛) or buffalo, is the country' s largest land animal. Its home is on the prairies. In 1830, there were an estimated 30 million to 60 million bison in the United States. By 1889, Americans had made the bison population to fewer than l,000 animals. Through great efforts, bison are being reintroduced to the prairies. They are also kept in zoos. The bison population has grown to several hundred thousand today.      Humans have put the prairie ecosystem in danger. Through constant farming, building, fire prevention, and ignorance( not knowing) of how the prairie works, the United States has lost much of its natural prairie. Through education and other work , we can hope to save some of it.

1. A prairie is a type of  ________.

A. plants B. animals C. grassland D. soil

2. What is the meaning of "interdependent ecosystem" in the first line?

A. All things in a prairie region depend on one another. B. Animals live on plants in a prairie region. C. Fire plays an important role in a prairie region. D. Soil has a close relationship with a prairie region.

3. By 1889, the bison population was ________.

A. about 30 million B. fewer than a thousand C. about 60 million D. several hundred thousand

4. We can leam from the article that ________.

A. fires may destroy a prairie and therefore must be prevented B. the interdependent ecosystem is both below and above ground C. the prairie ecosystem is in danger because of farming and building D. people haven't realized that they are losing their natural prairie

题型：阅读理解  难度：偏难

答案

1-4          CABB

据专家权威分析，试题“阅读理解。 A prairie is a type of grassland. Prairies are m..”主要考查你对  科教类阅读  等考点的理解。关于这些考点的“档案”如下：

科教类阅读

考点名称：科教类阅读

• 科普类的阅读：
  科普类的阅读理解包含介绍科学知识、社会知识的短文。阅读这类短文时，要以事实为中心进行思考，抓住事物的特征、用途、相互关系等。
  如果是介绍社会现象的文章，要掌握所谈现象的内涵。

• 答题技巧：
  1. 加强整体意识，把握文章的主要内容。在阅读的时候可给段落标上序号，并给重要的句子和
     关键词做上记号，尤其是各段中心句，为答题提供更快捷更多的信息源。
  2. 审清题干，发觉和把握试题中有效的提示性信息，确认命题的角度、阅读范围和答题方式。
  3. 定位阅读，强化对应意识。同时要注意原文利用和自我加工相结合。