英语四级阅读理解训练题带答案

　　阅读理解在英语四级考试中占有重要地位，提升英语阅读的能力就要加强平时的练习。下面学习啦小编为大家带来英语四级阅读理解训练题，供考生备考练习。

　　英语四级阅读理解训练题(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 (悬殊的差别. 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 (水蒸气. 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 ( 浓度. of these pollutants were altered byvariouschemical reactions; they became components in biogeochemical (生物地球化学的. 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

　　英语四级阅读理解训练题答案

　　BADDB

　　英语四级阅读理解训练题(二)

　　Acculturation, which begins at birth, is the process of teaching new generations of children the customs and values of the parents' culture. How people treat newborns, for example, can be indicative of cultural values. In the United States it is not uncommon for parents to put a newborn in a separate room that belongs only to the child. This helps to preserve parents' privacy and allows the child to get used to having his or her own room, which is seen as a first step toward personal independence. Americans traditionally have held independence and a closely related value, individualism, in high esteem. Parents try to instill these prevailing values in their children. American English expresses these value preferences: children should "cut the (umbilical) cord" and are encouraged not to be "tied to their mothers' apron strings." In the process of their socialization children learn to "look out for number one" and to "stand on their own two feet".

　　Many children are taught at a very early age to make decisions and be responsible for their actions. Often children work for money outside the home as a first step to establishing autonomy. Nine-or ten-year-old children may deliver newspapers in their neighborhoods and save or spend their earnings. Teenagers (13 to 18 years) may baby-sit neighbors' homes in order to earn a few dollar a week. Receiving a weekly allowance at an early age teaches children to budget their money, preparing them for future financial independence. Many parents believe that managing money helps children learn responsibility as well as appreciate the value of money.

　　21. According to this passage, the way people treat newborns _____.

　　A) is a sign of their customs

　　B) is an indication of their level of knowledge

　　C) symbolizes their social system

　　D) varies from culture to culture

　　22. The expression, "to cut the cord", is used to show that _____.

　　A) children don't like their parents

　　B) parents don't feel close to their children

　　C) parents would not like to live together with their children

　　D) independence from one's family is an important personal goal in USA

　　23. Children who are "tied to the apron strings" _____.

　　A) are caught in their mothers' aprons

　　B) must always wear an apron when they eat

　　C) are very dependent on their mothers

　　D) are independent from their parents

　　24. American people often let their children work for money outside the home at a very early age because _____.

　　A) children have to earn money to help the family

　　B) they need more money

　　C) they want them to begin establishing autonomy

　　D) children have to save money for future use

　　25. It can be inferred from this passage that _____.

　　A) Americans are money lovers

　　B) Americans admire independence

　　C) Americans are good at decision-making

　　D) Americans are all responsible

　　英语四级阅读理解训练题答案

　　1、A 2、D 3、C 4、C 5、B

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