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70天攻克考研英语阅读 DAY38

2006-7-28 01:04  

  Increasing reading speed

  Directions:Do the word recognition drills below.Note the words on the left,then underline them every time they appear in the same form to the right.No regression,no vocalization.Try to finish in 15 seconds or less.

  Starting Time:

  1. scenicscientific scenery scholastic scenic science

  2. nutrientnutrition nutritive nutrient nursery nutria

  3. doorstepdoorway doormat doorstop doorstep doorbell

  4. creaturecreation creative creator creature create

  5. traveltravels travelled traveller travel trial

  6. acidicacidity acidify acidulate acidic medallic

  7. measuremeasured measurable pleasure measure meaning

  8. neutralneutron neuter neutralize neutral neutronies

  9. streamstreaming streamy streamer streamlet stream

  10. indicateindicant indicator indicative indicate dictate

  Finishing Time: Total Reading Time:

  Errors:Check each line carefully for mistakes.

  ACID RAIN:What's the Solution?One of the wildest regions in the U.S.,far from civilization,is the Adirondack area of northern New York State. For years this isolated spot has had the reputation of being one of the best fishing spots in the U.S.

  As a boy 30 years ago,Bill Marleau first tramped through the Adirondack wilderness near his small cabin on Woods Lake. Thousands of sportsmen have stayed at his father's lodge nearby.

  But now Bill's 134 hectares (335 acres) of lakefront land have only scenic value. Gone are those huge trout that used to swim in the turbulent,nutrient rich water a short distance from his doorstep. Gone from the cool summer nights are the sounds of thousands of frogs and toads.

  And gone are the birds that once fed on those water creatures.

  Occasionally Bill sees a lone fisherman fruitlessly cast his bait into the empty waters of old lake. "I just don't have the heart to tell them,"he said. "This old lake's dead. It was killed years ago by acid rain. "What is acid rain?

  Acid rain is a popular term for precipitation in the form of rain,sleet,snow,or hail that is more acidic than normal. Acid rain is produced when atmospheric moisture combines with pollutants from power plants,factories,and automobiles.

  When fossil fuels such as coal and oil are burned,sulfur dioxide and nitrogen dioxide are produced. These two gases react with the water and oxygen in the atmosphere to form droplets of weak sulfuric and nitric acids.

  Carried by prevailing winds and weather conditions,clouds containing these droplets travel hundreds,sometimes thousands,of kilometers from the source of the pollutants. Recently scientists found that acid rain now affects huge areas of the Northern Hemisphere.

  Power plants and factories in the heavily industrialized regions of Ohio and Indiana are believed to be the source of the acid rain that killed Woods Lake along with hundreds of others in New York State and eastern Canada. Acid haze over Alaska is believed to come all the way from Japan. And precipitation as acidic as vinegar that falls on Scotland and Scandinavia probably originates in England.

  How Acidity Is MeasuredScientists measure the acidity of rain in pH units. A pH scale from 0 to 14 is used. Depending upon its chemical composition,a solution is either acidic,alkaline (basic),or neutral. Distilled water,which has a pH of 7,is neutral. Substances with pH values less than 7 are acidic,while those with values over 7 are alkaline.

  Normal rain water with a pH of 5.6 is slightly acidic. But after reacting with industrial pollutants,particularly sulfur dioxide,the pH of rain quickly drops.

  When acid rain falls to Earth,much of it ends up in lakes and ponds. In addition to falling directly into a lake,acid rain runs off land into streams and rivers that eventually flow into lakes and ponds. Once acid rain gets into them,its effects can be deadly.

  Studies started in 1975 in the Adirondacks indicate that salamanders and frogs are the first to die when the pH is lowered. Normally the pH of a lake is 8.0:slightly alkaline. When the pH drops to 7,the eggs of salamanders and frogs fail to hatch. At pH 6.6 snails begin to die.

  Bacteria that decompose leaf matter die too,and the leaf matter collects on the take bottom. As the acidity continues to drop,all the major food chains in the lake become affected. In time all the fish die.

  Eventually primitive,oxygenconsuming plants nearly choke out all other aquatic greenery. Algae and fungal growth that thrive in an acidic environment move in and cover the entire bottom of the now destroyed lake.

  Looking like blue vinegar,the lake is now an entirely changed ecosystem. It contains no life except for the fungal and algal growth and a few surface dwelling water bugs.

  Acid rain also affects plants on land.

  The effects of acid rain on terrestrial vegetation are not as well documented or as clearly understood as its effects on lakes. Experiments by Ellis B. Cowling of North Carolina State University,however,indicate that acid rain destroys the natural waxy coating on tree leaves and fruits. This destruction makes the plants more susceptible to disease.

  Acid Rain IncreasingThe acid rain problem seems to be getting worse. According to the Environmental Protection Agency,the amount of sulfur dioxide from power plants,autos,and factories is four times greater than it was 25 years ago. And federal air pollution regulations don't seem to be helping as much as had been expected.

  One problem is that the Clean Air Act of 1977 established air pollution standards based on measurements made at ground level. Environmentalists claim that this action has encouraged polluters to spread airborne pollutants at higher elevations instead of eliminating them altogether. Tall smokestacks,often more than 100 stories tall,now spread sulfur dioxide close to water carrying clouds.

  Power company officials stress,however,that the tall stacks significantly reduce air pollution in areas near the power plants. And the officials also point to clean up efforts currently underway in the industry to reduce the amount of pollutants.

  New,cleaner burning furnaces have been installed in recently constructed power plants. Scrubbers are also available that can be installed on industrial and power plant smokestacks. The scrubbers can remove up to 85 percent of the sulfur given off from stacks. Meanwhile,experiments continue in the development of cleaner sources of fuel such as low sulfur,liquid coal.

  What can be done about lakes that are already acidic? Acidity can be reduced by dropping tons of lime (an alkaline substance) into the lake water. However, this solution is very expensive. Less optimistic scientists are trying to breed acid tolerant fish. These,measures,however are far from ideal. The solution to acid rain can only come from cooperation between industry,Government,and scientists.

  ——from Current Science,Jan. 7,1981

  Time: 989 words=wpm

  minutes

  EXERCISESⅠ。READING COMPREHENSION

  Select the answer which is most accurate according to the question given in the passage.

  1. For what reason is the Adirondack area called one of the wildest regions in the U. S?

  A. Only primitive people dwell in the area.

  B. Acid rain has produced a deadly effect upon this virgin

  C. The area has never been exploited for either industrial or cultural purposes.

  D. Only wild animals are found in the area.

  2. It can be inferred from the passage that the Adirondack now is

  A. lacking in fishB. deadly quiet

  C. alive with wild animals                      D. a summer resort

  3. Acid rain can occur .

  A. only in the form of rainB. in the form of rain or sleet

  C. in the form of snow or hailD. both B and C

  4. Tiny drops of weak sulfuric and nitric acids are formed when

  A. sulfur and nitrogen oxides react with each other

  B. fossil fuels are burned in the open air

  C. sulfur and nitrogen oxides react with the water vapor and oxygen in the atmosphere

  D. sulfur dioxide and nitrogen dioxide combine with each other in lakes or ponds

  5. Which of the following is not meant by the author?

  A. Acid rain is found to have affected vast areas of the Northern Hemisphere.

  B. Even though a region is thousands of miles away from the source of the nonpollutants,it can nevertheless be affected by acid rain.

  C. Power plants,automobiles and factories are known to be the major source of acid rain.

  D. A region having no industry at all is entirely free from acid rain.

  6. The pH value of .

  A. pure water is 7 B. nonpolluted rain water is 7

  C. an alkaline solution is below 7        D. an acidic solution is above 7

  7. Among all the living things in the Adirondacks, are most susceptible to acid rain.

  A. salamanders and frogs B. trout and fishhunting birds

  C. algae and fungus D. bacteria and water bugs

  8. A(n) environment is favorable to .

  A. acidic……algae and fungal growthB. weak alkaline……salamanders and frogs

  C. acidic……snailsD. both A and B

  9. According to the passage,the Clean Air Act of 1977 has encouraged polluters to

  A. eliminate pollutants B. build higher smokestacks

  C. install dusters D. use atomic energy

  10. Used in the passage,a cleaner burning furnace refers to a furnace

  A. in which only clean fossil fuels are burnt

  B. inside which a cleaner is installed

  C. in which coal or oil burns thoroughly

  D. none of the above

  11. Which of the following is the best solution to acid rain?

  A. Unloading tons of lime into the lake water

  B. Breeding acid tolerant fish in the present acidic lakes.

  C. Building higher smokestacks.

  D. Promoting cooperation between industry,Government and scientists.

  Ⅱ。 CONTEXTUAL REFERENCE

  Read the following article and figure out the meaning of the words in italics using the context given and word building skills.

  Substances consist of small parts,or particles,which are known as molecules. Molecules are composed of atoms. Some substances,like salt and water,have molecules which can be analyzed further into other substances. If a molecule of water is analyzed,for example,it will be found to consist of two atoms of hydrogen and one atom of oxygen. Substances whose molecules are composed of atoms of other substances are known as compounds. Other substances have molecules which cannot be broken down into atoms of other substances,and these are called elements.Hydrogen and oxygen,for example,are elements. Thus if a molecule of oxygen is analyzed it will be found to consist of only atoms of oxygen and not of any other substance. There are 92 natural elements. Some are metallic solids like copper,iron and lead;some are nonmetallic solids like sulphur and carbon;and some are gases like oxygen,hydrogen and nitrogen.

  Compounds can be divided into a number of different classes,the most important of which are acids,bases and salts. An acid is a compound of hydrogen which will attack some metals and liberate hydrogen when magnesium is dissolved in it. An acid will turn litmus red and it will react with washing soda,giving off carbon dioxide. A further characteristic of acids is that they have a burning effect on substances like wood,paper,cloth and human skin. Bases are a class of substances, consisting mainly of oxides and hydroxides of metals,which will neutralize acids if  used in proper quantities and form salt - like substances in the process. A special class of bases,called alkalis,will dissolve in water and form a solutions which turn red litmus blue. Alkalis form solution which feels soapy and which will dissolve oily and greasy substances,and for this reason they are frequently used for cleaning.

  ——from English in Physical Science by J.P.B.Allen,Oxford University Press,1974

  Ⅲ。CLOZE

  Complete the following passage by filling in the blanks with appropriate words.

  "Chief,did you know that Current Science made one of the largest surveys of the acid rain problem ever undertaken?" asks Molly Kule.

  "In 1973 pH indicator kits (含有pH指示剂容器) were mailed   1  kids throughout the country. When the results were     2, more than 16000 people      3     1100 schools had taken 4. The students     5     the acidity of the rain     6     in their area. Then this information was 7     into a computer to     8     the acid rain map."

  "In 1973 scientists thought that the relationship     9     acid rain and the death of lakes was a simple   10. They thought that if the rain were   11, the lake water would become acidic     12. And the fish would ultimately   13   when the acidity increased   14   their tolerance."

  "More recent research,  15, indicates that the   16   between acid rain and the death of lakes is not   17   simple. The extent   18   which a lake becomes acidic also depends  19   the type of rock     20     it.

  "If the surrounding bedrock is soft and alkaline,like limestone,a lake may be able to neutralize,or counteract the acidic water coming into it. If,however,the surrounding rock is relatively hard and non alkaline,like granite,acidic rain will make the lake more acidic. Eventually enough acid may fall to virtually kill the lake. "

  ——from Current,Science,Jan. 7,1981

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