一、考點描述

　　科普類文章是高考英語的常考題材，每年高考都有所涉及，如2005年的江蘇卷在五篇閱讀文章中就有兩篇是關于科普文章的閱讀。因此，同學們在平時的學習中一定要對此引起高度的重視。

　　二、材料特點

　　這類文章的總體特點是：科技詞匯多，句子結構復雜，理論性強，邏輯嚴謹。具體說來它有以下幾個特點：

　　1. 文章中詞匯的意義比較單一、穩(wěn)定、簡明，不帶感情色彩，具有單一性和準確性的特點。這類文章通常不會出現(xiàn)文學英語中采用的排比、比喻、夸張等修辭手法，一詞多義的現(xiàn)象也不多見。

　　2. 句子結構較復雜，語法分析較困難。為了描述一個客觀事物，嚴密地表達自己的思想，作者經(jīng)常會使用集多種語法現(xiàn)象于一體的長句。

　　3. 常使用被動語態(tài)，尤其是一些慣用被動句式。

　　三、命題特點

　　科普類閱讀的主要命題形式有事實細節(jié)題、詞義猜測題、推理判斷題以及主旨概括題等，其中推理判斷題居多。

　　四、應對策略

　　1. 要想做好科普英語閱讀理解題，同學們就要注意平時多讀科普知識類文章，學習科普知識，積累常見的科普詞匯，從根本上提高科普英語的閱讀能力。

　　2. 要熟悉科普類文章的結構特點�？破疹愇恼乱话阌蓸祟}(Headlines)，導語(Introductions)，背景( Background)，主體(Main body)和結尾(Ends)五部分構成。標題是文章中心思想高度而又精辟的概括，但根據(jù)歷年的高考真題情況來看，這類閱讀理解材料一般不給標題，而要同學們選擇標題。導語一般位于整篇文章的首段。背景交待一個事實的起因。主體則對導語概括的事實進行詳細敘述。這一部分命題往往最多，因此，閱讀時，同學們要把這部分作為重點。結尾往往也是中心思想的概括，并與導語相呼應，命題者常在此要設計一道推理判斷題。

　　3. 在進行推理判斷時，同學們一定要以閱讀材料所提供的科學事實為依據(jù)，同時所得出的結論還應符合基本的科普常識。

　　五、真題賞析

　　江蘇卷

　　Animals can move from place to place, but plants cannot. When an animal is under attack, it can run away or fight back. Plants certainly cannot run away, and they lack teeth and claws. But plants can defend themselves by using both physical and chemical means.

　　Some plants have their own ways to keep animals away. For example, the leaves of the holly plant have sharp spines(刺) that discourage grass-eating animals. Holly leaves on lower branches have more spines than leaves on upper branches. This is because the lower leaves are easier for most animals to reach.

　　Some plants, such as the oak tree, have thick and hard leaves that are difficult for animals to eat. Some grasses may contain a sandy material; eating such grasses wears down the animal’s teeth.

　　Many plants also have chemical defenses. Some plants produce chemicals that taste bitter or cause an unpleasant reaction. Some plants may fight against an attack by increasing the production of these chemicals. When a caterpillar (毛蟲) bites a tobacco leaf, the leaf produces a chemical messenger. This messenger sends to the roots the information to produce more nicotine. The higher levels of nicotine discourage the caterpillar.

　　Many plants depend on both physical and chemical defenses. A certain plant in China, for instance, has prickly (多刺的) leaves, and each prickle contains poisonous venom (毒液). A single experience with this kind of plant will teach an animal to stay away from it in the future.

　　68. The holly plant has more spines on the lower leaves because most animals________.

　　A. are not tall enough      B. like the lower leaves only

　　C. are not clever enough    D. can get the lower leaves easily

　　69. To defend themselves, oak trees use________.

　　A. chemical means        B. physical means

　　C. bitter chemicals        D. sandy materials

　　70. How does tobacco protect itself against an attack from a caterpillar?

　　A. Its leaves fight against the attack by physical means.

　　B. Its roots send a messenger to discourage the caterpillar.

　　C. Its roots increase the production of nicotine when it is attacked.

　　D. Its leaves produce poisonous sand to drive the caterpillar away.

　　71. What would be the best title for this passage?

　　A. Plants and Animals       B. How Plants Defend Themselves

　　C. Attacks and Defenses      D. How Animals Eat Plant Leaves

　　【答案與解析】本文主要介紹一些植物是如何通過物理和化學的方式保護自己不受外界侵害的。

　　68. D。事實細節(jié)題。根據(jù)第2段最后一句…the lower leaves are easier for most animals to reach可知答案。

　　69. B。推理判斷題。根據(jù)第3段中的…oak tree, have thick and hard leaves that are difficult for animals to eat可推知，又厚又硬的樹葉屬于植物自我保護的物理手段。

　　70. C。推理判斷題。根據(jù)第四段可知，tobacco保護自己不受毛蟲侵害的辦法是產(chǎn)生更多的nicotine。

　　71. B。主旨概括題。因為整篇文章都在講植物是怎樣保護他們自己的，故選B。

　　六、模擬訓練

　　A

　　Walk through the Amazon rainforest today and you will find it is steamy, warm, damp and thick. But if you had been around 15, 000 years ago, during the last ice age, would it have been the same? For more than 30 years, scientists have been arguing about how rainforests like the Amazon might have reacted (反應) to the cold, dry cli-mates of the ice ages, but until now, no one has reached a satisfying answer.

　　Rainforests like the Amazon are important for mopping up CO2 from the atmos-phere and helping to slow global warming. Currently the trees in the Amazon take in around 500 million tons of CO2 each year: equal to the total amount of CO2 giving off in the UK each year. But how will the Amazon react to future climate change? If it gets drier, will it still survive and continue to draw down CO2? Scientists hope that they will be able to learn in advance how the rainforest will manage in the future by understanding how rainforests reacted to climate change in the past.

　　Unfortunately, getting into the Amazon rainforest and collecting information are very difficult. To study past climate, scientists need to look at fossilized pollen, kept in lake muds. Going back to the last ice age means drilling deep down into lake sediments(沉淀物) which requires specialized equipment and heavy machinery. There are very few roads and paths, or places to land helicopters and aero planes. Rivers tend to the easiest way to enter the forest, but this still leaves vast areas between the rivers com-pletely unsampled (未取樣). So far, only a handful of cores have been drilled that go back to the last ice age and none of them provide enough information to prove how the Amazon rainforest reacts to climate change.

　　1. The underlined phrase “mopping up” in the second paragraph means “______”.

　　A. cleaning up    B. taking in    C. wiping out   D. giving out

　　2. How will the Amazon rainforest react to future climate change?

　　A. It’ll get drier and continue to remove CO2.

　　B. It’ll remain steamy, warm, damp and thick.

　　C. It’ll get warmer and then colder and drier.

　　D. There is no exact answer up to present.

　　3. What’s the main idea of the last paragraph?

　　A. It’s important to drill deep down into lake sediments to collect information.

　　B. It’s impossible to prove how climate changes in the Amazon rainforest.

　　C. It’s hard to collect information for studies of the past climate in the Amazon rainforest.

　　D. It’s necessary to have specialized equipment and machinery to study the past cli-mate.

　　4. The best title for this passage may probably be _____.

　　A. Studies of the Amazon           B. Climates of the Amazon

　　C. Secrets of the Rainforests       D. Changes of the Rainforests

　　【答案與解析】本文主要介紹了熱帶雨林對氣候的影響。

　　1. B。詞義猜測題。根據(jù)第二段中的 helping to slow global warming，同時結合化學知識可推知 mopping up 的意思是“吸入”。另外，文章中的…currently the trees in Amazon take in around 500 million tones of CO2 each year 也暗示 mop up 和 take in 的意思相同。

　　2. D。事實細節(jié)題。根據(jù)文章第2段的內(nèi)容(尤其是最后一句話)可推知此題最佳答案為D。

　　3. C。主旨大意題。根據(jù)文章最后一段中的So far, only a handful of cores have been drilled 可知，資料收集不是很容易。

　　4. C。主旨大意題。文章主要講的是亞馬孫熱帶雨林難以預料的變化，所以選C為佳。

　　B

　　Terrible weather, melting(融化的) snow and gathering clouds may be signs of global warming. The average temperature on Earth for last year was the second warmest since written records began 140 years ago.

　　The global average surface temperature in 2001 was 14.42 degrees centigrade, the World Meteorological Organization said. The record, set in 1998, was 14.58 degrees centigrade.

　　“Temperatures are getting hotter, and they are getting hotter faster now than at any time in the past, ” said Michel Jarraud, a WMO official.

　　Carbon dioxide(二氧化碳) produced from burning fuels is the most common of the so-called greenhouse gases. The growing concentration(集中) in the atmosphere of these gases is thought to be warming the Earth. “Most of the causes of global warming are due to human action, ” said Ken Davidson, director of WMO’s climate programme department.

　　Every year, large amounts of gases produced by factories, cars and burning trees hold in too much heat and cause global warming. Many scientists believe the warming, if not stopped, will cause extreme climate changes this century.

　　Throughout the world, the spreading of particular diseases and other threats(威脅) to human health depend largely on local climates. Extreme temperatures can directly cause loss of life. Warm temperatures can increase air and water pollution, which in turn can harm human health.

　　In the Earth’s atmosphere there are tiny amounts of gases called greenhouse gases. These gases hold in the heat that comes up from the sun-warmed Earth. As cities have increased in size and population, factories and industries in the world have grown. People need more and more electricity, cars and other things. So more greenhouse gases have been added to the atmosphere. This causes more heat to be trapped than in the past. This is called the greenhouse effect.

　　1. The subject discussed in the passage is _______.

　　A. the growing population of the world

　　B. the global average surface temperature

　　C. the increasing greenhouse effect

　　D. the causes of air and water pollution

　　2. according to a WMO official, it is ________ that should be blamed for global warming.

　　A. modern factories impressive            B. mankind

　　C. carbon dioxide                               D. burning fuels

　　3. The rising of the earth temperature will finally result in _______.

　　A. the spreading of particular diseases  B. air and water pollution

　　C. extreme climate changes                 D. loss of life

　　4. Which of the following is true according to the passage?

　　A. Air and water pollution is caused by global warming.

　　B. Greenhouse gases do no good to human beings

　　C. With the air getting hotter, people need more and more electricity, cars and other things.

　　D. The average temperature on Earth for 1998 was the warmest according to written records

　　【答案與解析】本文向我們介紹了由于環(huán)境污染而引起的全球變暖的現(xiàn)象。

　　1. C。主旨大意題。本文討論的是全球變暖的現(xiàn)象，而造成這種現(xiàn)象的原因是溫室效應，文章在最后也對溫室效應做了解釋，故答案為C。

　　2. B。事實細節(jié)題。根據(jù)第四段中的 most of the causes of global warming are due to human action, said Ken Davidson, director of WMO’s climate programme department可知答案為B。

　　3. D。事實細節(jié)題。根據(jù)第六段中的 Extreme temperatures can directly cause loss of life可知此題的最佳答案為D。

　　4. D。事實細節(jié)題。根據(jù)第二段中的 The record, set in 1998, was 14.58 degrees centigrade可知答案D正確。