大学英语四级级阅读理解每日一练
一
Recent rearch has claimed that an e_cess of
positive ions in the air can have an ill effect on peoples physical or psychological health. What are positive ions Well the air is full of ions electrically charged particles and generally there is a rough balance between the positive and the negative charged. But sometimes this balance bees disturbed and a larger proportion of positive ions are found. This happens naturally before thunderstorm earthquakes when winds such as the Mistral Hamsin or Sharav are blowing in certain countries. Or it can be caud by a build-up of static electricity indoors from carpets or clothing made of man-made fibres or from TV ts duplicators or puter display screens. When a large number of positive ions are prent in the air many people e_perience unpleasant effects such as headaches fatigue irritability and some particularly nsitive people suffer naua or even mental disturbance. Animals are also affected
particularly before earthquakes snakes have been obrved
to e out of hibernation rats to flee from their burrows dogs howl and cats jump about unaccountably. Thi
s has led the US Geographical Survey to fund a work of volunteers to watch animals in an effort to foree such disasters before they hit vulnerable areas such as California. Converly when large numbers of negative ions are prent then people have a feeling of well-being. Natural conditions that produce the large amounts are near the a clo to waterfalls or fountains or in any place where water is sprayed or forms a spray. This probably accounts for the beneficial effect of a holiday by the a or in the mountains with tumbling streams or waterfalls. To increa the supply of negative ions indoors some scientists remend the u of ionirs：
small portable machines which generate negative ions. They claim that ionirs not only clean and refresh the air but also improve the health of people nsitive to
e_cess positive ions. Of cour there are the detractors other scientists who dismiss such claims and are
skeptical about negative/positive ion rearch. Therefore people can only make up their own minds by obrving the effects on themlves or on others of a negative rich or
poor environment. After all it is debatable whether depending on ismic readings to anticipate earthquakes
is more effective than watching the cat.
1.What effect does e_ceeding positive ionization have on some people
A.They think they are insane.
B.They feel rather bad-tempered and short-fusd.
C.They bee violently sick.
D.They are too tired to do anything.
2.In accordance with the passage static electricity can be caud by___.
A.using home-made electrical goods.
B.wearing clothes made of natural materials.
C.walking on artificial floor coverings.
a puter.
3.A high negative ion count is likely to be found___.
B.clo to a slow-flowing river.
C.high in some barren mountains.
D.by a rotating water sprinkler.
4.What kind of machine can generate negative ions indoors
A.Ionirs.
B.Air-conditioners.
C.E_haust-fans
D.Vacuum pumps.
5.Some scientists believe that___.
A.watching animals to anticipate earthquakes is more effective than depending on ismography.
B.the unusual behavior of animals cannot be trusted.
D.earthquake
答案：BCDAA
二
Which is safer-staying at home traveling to work on public transport or working in the office Surprisingly each of the carries the same risk which is very low. However what about flying pared 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 cau death to tho living nearby. It is this which makes chemical accidents so newsworthy. Fortunately they are e_tremely rare. The most
famous ones happened at Te_as City (1947)Fli_borough (1974) Seveso (1976) Peme_ (1984) and Bhopal (1984)。
Some of the 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 Fli_borough. The worst accident of all was Bhopal where up to 3000 were killed. The Te_as City e_plosion of fertilizer killed 552. The Peme_ fire at a storage plant for natural gas in the suburbs of Me_ico City took 542 lives just a month before the unfortunate event at Bhopal.
Some e_perts have discusd the accidents and ud each accident to illustrate a particular danger. Thus the Te_as City e_plosion was caud by tons of ammonium nitrate(硝酸铵)which is safe unless stored in great quantity. The Fli_borough fireball was the fault of management which took risks to keep production going during esntial repairs. The Seveso accident shows what happe
ns 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 Peme_ fire was made wor by an overloaded site in an overcrowded suburb. The fire t
