四級考試閱讀理解專練題及答案

　　閱讀能力歷來是英語四級考試重點考察的英語能力之一，提高英語閱讀能力，對於提高四級考試成績非常重要。下面小編為大家帶來四級考試閱讀理解專練題，供考生閱讀練習。

　　四級考試閱讀理解專練題一

　　A useful definition of an air pollutantis a compound added directly or indirectly by humans to the atmospherein suchquantities as to affect humans, animals, vegetation, or material adversely ***有害地.. Air pollution requires avery flexibledefinition that permits continuous change. When the first air pollution lawswere established inEngland in the fourteenth century, air pollutants werelimited to compounds that could be seen or smelled—a farcry ***懸殊的差別. from the extensive list of harmful substances known today. Astechnology has developed andknowledge of the health aspects of variouschemicals has increased, the list of air pollutants has lengthened. Inthefuture, even water vapor ***水蒸氣. might be consideredan air pollutant under certain conditions.

　　Many of the more important airpollutants, such as sulfur oxides, carbon monoxide, and nitrogen oxides,arefound in nature. As the Earth developed, the concentrations *** 濃度. of these pollutants were altered byvariouschemical reactions; they became components in biogeochemical ***生物地球化學的. cycles. These serve as an airpurification scheme by allowing thecompounds to move from the air to the water or soil. On a global basis,nature'soutput of these compounds dwarfs that resulting from human activities. However,human productionusually occurs in a localized area, such as a city.

　　In this localized region, human outputmay be dominant and may temporarily overload the natural purificationscheme ofthe cycles. The result is an increased concentration of noxious *** 有害的. chemicals in the air. Theconcentrations atwhich the adverse effects appear will be greater than the concentrations thatthe pollutants wouldhave in the absence of human activities. The actualconcentration need not be large for a substance to be apollutant; in fact thenumerical value tells us little until we know how much of an increase thisrepresents over the concentration that would occur naturally in the area. Forexample, sulfur dioxide has detectable health effects at0.08 parts per million***ppm., which is about 400 times its natural level.Carbon monoxide, however, has a naturallevel of 0.1 ppm and is not usually apollutant until its level reaches about 15 ppm.

　　61、It can be inferred from thefirst paragraph that _________

　　A.water vapor is an air pollutant in localized areas

　　B.the definition of air pollution will continue to change

　　C.a substance becomes an air pollutant only in cities

　　D.most air pollutants today can be seen or smelled

　　62、In what way can naturalpollutants play an important role in controlling air pollution?

　　A.They function as part of a purification process.

　　B.They are dwarfed by the pollutants produced by human activities.

　　C.They are less harmful to living beings than are other pollutants.

　　D.They have existed since the Earth developed.

　　63、According to the passage,the numerical value Of the concentration level of a substance is only useful if

　　A.the other substances in the area are known

　　B.it is a localized area

　　C.it can be calculated quickly

　　D.the naturally occurring level is also known

　　64、Which of the following isbest supported by the passage?

　　A.To effectively control pollution, local government should regularlyrevise the air pollution laws.

　　B.One of the most important steps in preserving natural lands is tobetter enforce air pollution laws.

　　C.Scientists should be consulted in order to establish uniform limitsfor all air pollutants.

　　D.Human activities have great impact on air pollution.

　　65、The passage mainlydiscusses _________

　　A.the economic impact on air pollution

　　B.how much damage air pollutants can cause

　　C.what constitutes an air pollutant

　　D.the quantity of compounds added to the atmosphere

　　四級考試閱讀理解專練題答案

　　BADDB

　　四級考試閱讀理解專練題二

　　Now let us look at how we read. When we read a printed text, our eyes move across a page in short, jerky movement. We recognize words usually when our eyes are still when they fixate. Each time they fixate, we see a group of words. This is known as the recognition span or the visual span. The length of time ofr which the eyes stop ---the duration of the fixation ----varies considerably from person to person. It also vaies within any one person according to his purpose in reading and his familiarity with the text. Furthermore, it can be affected by such factors as lighting and tiredness.

　　Unfortunately, in the past, many reading improvement courses have concentrated too much on how our eyes move across the printed page. As a result of this misleading emphasis on the purely visual aspects of reading, numerous exercises have been devised to train the eyes to see more words at one fixation. For instance, in some exercises, words are flashed on to a screen for, say, a tenth or a twentieth of a second. One of the exercises has required students to fix their eyes on some central point, taking in the words on either side. Such word patterns are often constructed in the shape of rather steep pyramids so the reader takes in more and more words at each successive fixation. All these exercises are very clever, but it’s one thing to improve a person’s ability to see words and quite another thing to improve his ability to read a text efficiently. Reading requires the ability to understand the relationship between words. Consequently, for these reasons, many experts have now begun to question the usefulness of eye training, especially since any approach which

　　trains a person to read isolated words and phrases would seem unlikely to help him in reading a continuous text.

　　1. The time of the recognition span can be affected by the following facts except ________ .

　　A. one’s familiarity with the text

　　B. one’s purpose in reading

　　C. the length of a group of words

　　D. lighting and tiredness

　　2. The author may believe that reading ______.

　　A. requires a reader to take in more words at each fixation

　　B. requires a reader to see words more quickly

　　C. demands an deeply-participating mind

　　D. demands more mind than eyes

　　3 What does the author mean by saying “but it’s one thing to improve a person’s ability to see words and quite another thing to improve his ability to read a text efficiently.” in the second parapraph?

　　A. The ability to see words is not needed when an efficient reading is conducted.

　　B. The reading exercises mentioned can’t help to improve both the ability to see and to comprehend words.

　　C. The reading exercises mentioned can’t help to improve an efficient reading.

　　D. The reading exercises mentioned has done a great job to improve one’s ability to see words.

　　4. Which of the following is NOT true?

　　A. The visual span is a word or a group of words we see each time.

　　B. Many experts began to question the efficiency of eye training.

　　C. The emphasis on the purely visual aspects is misleading.

　　D.The eye training will help readers in reading a continuous text.

　　5. The tune of the author in writing this article is ________

　　A critical

　　B neutral