Which is safer-staying at home， traveling to work on public transport， or working in the office? Surprisingly， each of these carries the same risk， which is very low. However， what about flying compared to working in the chemical industry? Unfortunately， the former is 65 times riskier than the latter! In fact， the accident rate of workers in the chemical industry is less than that of almost any of human activity， and almost as safe as staying at home.

The trouble with the chemical industry is that when things go wrong they often cause death to those living nearby. It is this which makes chemical accidents so newsworthy. Fortunately， they are extremely rare. The most famous ones happened at Texas City (1947)，Flixborough (1974)， Seveso (1976)， Pemex (1984) and Bhopal (1984)。

Some of these are always in the minds of the people even though the loss of life was small. No one died at Seveso， and only 28 workers at Flixborough. The worst accident of all was Bhopal， where up to 3，000 were killed. The Texas City explosion of fertilizer killed 552. The Pemex fire at a storage plant for natural gas in the suburbs of Mexico City took 542 lives， just a month before the unfortunate event at Bhopal.

Some experts have discussed these accidents and used each accident to illustrate a particular danger. Thus the Texas City explosion was caused by tons of ammonium nitrate(硝酸铵)，which is safe unless stored in great quantity. The Flixborough fireball was the fault of management， which took risks to keep production going during essential repairs. The Seveso accident shows what happens if the local authorities lack knowledge of the danger on their doorstep. When the poisonous gas drifted over the town， local leaders were incapable of taking effective action. The Pemex fire was made worse by an overloaded site in an overcrowded suburb. The fire set off a chain reaction os exploding storage tanks. Yet， by a miracle， the two largest tanks did not explode. Had these caught fire， then 3，000 strong rescue team and fire fighters would all have died.

1.Chemical accidents are usually important enough to be reported as news because ____.

A.they are very rare

B.they often cause loss of life

C.they always occur in big cities

D.they arouse the interest of all the readers

2.Which of the following statements is true?

A.Working at the office is safer than staying at home.

B.Traverlling to work on public transport is safer than working at the office.

C.Staying at home is safer than working in the chemical industry.

D.Working in the chemical industry is safer than traveling by air.

3.According to passage， the chemical accident that caused by the fault of management happened at ____.

A.Texas city B.Flixborough C.Seveso D.Mexico City

4.From the discussion among some experts we may coclude that ____.

A.to avoid any accidents we should not repair the facilities in chemical industry

B.the local authorities should not be concerned with the production of the chemical industry

C.all these accidents could have been avoided or controlled if effective measure had been taken

D.natural gas stored in very large tanks is always safe

5.From the passage we know that ammonium nitrate is a kind of ____.

A.natural gas， which can easily catch fire

B.fertilizer， which can't be stored in a great quantity

C.poisonous substance， which can't be used in overcrowded areas

D.fuel， which is stored in large tanks

Wecanconcludefromthepassagethat________.

While doing calculation for the project, the designers____a new solution to a geological problem.

What does the future hold for the problem of housing? A good deal depends, of course, on the meaning of “future”. If one is thinking in terms of science fiction and the space age, it is at least possible to assume that man will have solved such trivial and earthly problems as housing. Writers of science fiction, from H.G. Wells onwards, have had little to say on the subject. They have conveyed the suggestion that men will live in great comfort, with every conceivable apparatus to make life smooth, healthy and easy, if not happy. But they have not said what his house will be made of. Perhaps some new building material, as yet unimagined, will have been discovered or invented at least. One may be certain that bricks and mortar(泥灰，灰浆) will long have gone out of fashion.

But the problems of the next generation or two can more readily be imagined. Scientists have already pointed out that unless something is done either to restrict the world’s rapid growth in population or to discover and develop new sources of food (or both), millions of people will be dying of starvation or at the best suffering from underfeeding before this century is out. But nobody has yet worked out any plan for housing these growing populations. Admittedly the worst situations will occur in the hottest parts of the world, where housing can be light structure or in backward areas where standards are traditionally low. But even the minimum shelter requires materials of some kind and in the teeming, bulging towns the low-standard “housing” of flattened petrol cans and dirty canvas is far more wasteful of ground space than can be tolerated.

Since the war, Hong Kong has suffered the kind of crisis which is likely to arise in many other places during the next generation. Literally millions of refugees arrived to swell the already growing population and emergency steps had to be taken rapidly to prevent squalor(肮脏)and disease and the spread crime. The city is tackling the situation energetically and enormous blocks of tenements(贫民住宅)are rising at an astonishing aped. But Hong Kong is only one small part of what will certainly become a vast problem and not merely a housing problem, because when population grows at this rate there are accompanying problems of education, transport, hospital services, drainage, water supply and so on. Not every area may give the same resources as Hong Kong to draw upon and the search for quicker and cheaper methods of construction must never cease.

1.What is the author’s opinion of housing problems in the first paragraph?

A.They may be completely solved at sometime in the future.

B.They are unimportant and easily dealt with.

C.They will not be solved until a new building material has been discovered.

D.They have been dealt with in specific detail in books describing the future.

2.The writer is sure that in the distant future ___.

A.bricks and mortar will be replaced by some other building material.

B.a new building material will have been invented.

C.bricks and mortar will not be used by people who want their house to be fashionable.

D.a new way of using bricks and mortar will have been discovered.

3.The writer believes that the biggest problem likely to confront the world before the end of the century ___.

A.is difficult to foresee.

B.will be how to feed the ever growing population.

C.will be how to provide enough houses in the hottest parts of the world.

D.is the question of finding enough ground space.

4.When the writer says that the worst situations will occur in the hottest parts of the world or in backward areas, he is referring to the fact that in these parts ___.

A.standards of building are low.

B.only minimum shelter will be possible.

C.there is not enough ground space.

D.the population growth will be the greatest.

5.Which of the following sentences best summarizes Paragraph 3?

A.Hong Kong has faced a serious crisis caused by millions of refugees.

B.Hong Kong has successfully dealt with the emergency caused by millions of refugees.

C.Hong Kong’s crisis was not only a matter of housing but included a number of other problems of population growth.

D.Many parts of the world may have to face the kind of problems encountered by Hong Kong and may find it much harder to deal with them.

Recentresearchhasclaimedthatanexcessofpositiveionsintheaircanhaveanilleffectonpeople’sphysicalorpsychologicalhealth.Whatarepositiveions?Well,theairisfullofions,electricallychargedparticles,andgenerallythereisaroughbalancebetweenthepositiveandthenegativecharged.Butsometimesthisbalancebecomesdisturbedandalargerproportionofpositiveionsarefound.Thishappensnaturallybeforethunderstorm,earthquakeswhenwindssuchastheMistral,HamsinorSharavareblowingincertaincountries.Oritcanbecausedbyabuild-upofstaticelectricityindoorsfromcarpetsorclothingmadeofman-madefibres,orfromTVsets,duplicatorsorcomputerdisplayscreens.

Whenalargenumberofpositiveionsarepresentintheairmanypeopleexperienceunpleasanteffectssuchasheadaches,fatigue,irritability,andsomesensitivepeoplesuffernauseaorevenmentaldisturbance.Animalsarealsoaffected,particularlybeforeearthquakes,snakeshavebeenobservedtocomeoutofhibernation,ratstofleefromtheirburrows,dogshowlandcatsjumpaboutunaccountably.ThishasledtheUSGeographicalSurveytofundanetworkofvolunteerstowatchanimalsinanefforttoforeseesuchdisastersbeforetheyhitvulnerableareassuchasCalifornia.

Conversely,whenlargenumbersofnegativeionsarepresent,thenpeoplehaveafeelingofwell-being.Naturalconditionsthatproducetheselargeamountsarenearthesea,closetowaterfallsorfountains,orinanyplacewherewaterissprayed,orformsaspray.Thisprobablyaccountsforthebeneficialeffectofaholidaybythesea,orinthemountainswithtumblingstreamsorwaterfalls.

Toincreasethesupplyofnegativeionsindoors,somescientistsrecommendtheuseofionisers:smallportablemachines,whichgeneratenegativeions.Theyclaimthationisersnotonlycleanandrefreshtheairbutalsoimprovethehealthofpeoplesensitivetoexcesspositiveions.Ofcourse,therearethedetractors,otherscientists,whodismisssuchclaimsandareskepticalaboutnegative/positiveionresearch.Thereforepeoplecanonlymakeuptheirownmindsbyobservingtheeffectsonthemselves,oronothers,ofanegativerichorpoorenvironment.Afterallitisdebatablewhetherdependingonseismicreadingstoanticipateearthquakesismoreeffectivethanwatchingthecat.

1.Whateffectdoesexceedingpositiveionizationhaveonsomepeople?

A.Theythinktheyareinsane.

B.Theyfeelratherbad-temperedandshort-fussed.

C.Theybecomeviolentlysick.

D.Theyaretootiredtodoanything.

2.Inaccordancewiththepassage,staticelectricitycanbecausedby___.

A.usinghome-madeelectricalgoods.

B.wearingclothesmadeofnaturalmaterials.

C.walkingonartificialfloorcoverings.

D.copyingTVprogramsonacomputer.

3.Ahighnegativeioncountislikelytobefound___.

A.nearapoundwithawaterpump.

B.closetoaslow-flowingriver.

C.highinsomebarrenmountains.

D.byarotatingwatersprinkler.

4.Whatkindofmachinecangeneratenegativeionsindoors?

A.Ionisers.

B.Air-conditioners.

C.Exhaust-fans

D.Vacuumpumps.

5.Somescientistsbelievethat___.

A.watchinganimalstoanticipateearthquakesismoreeffectivethandependingonseismography.

B.theunusualbehaviorofanimalscannotbetrusted.

C.neitherwatchingnorusingseismographsisreliable.

D.earthquake