Recent research has claimed that an excess 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 becomes 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 caused by a build-up of static electricity indoors from carpets or clothing made of man-made fibres, or from TV sets, duplicators or computer display screens.
When a large number of positive ions are present in the air many people experience unpleasant effects such as headaches, fatigue, irritability, and some particularly sensitive people suffer nausea or even mental disturbance. Animals are also affected, particularly before earthquakes, snakes have been observed to come out of hibernation, rats to flee from their burrows, dogs howl and cats jump about unaccountably. This has led the US Geographical Survey to fund a network of volunteers to watch animals in an effort to foresee such disasters before they hit vulnerable areas such as California.
Conversely, when large numbers of negative ions are present, then people have a feeling of well-being. Natural conditions that produce these large amounts are near the sea, close 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 sea, or in the mountains with tumbling streams or waterfalls.
To increase the supply of negative ions indoors, some scientists recommend the use of ionisers: small portable machines, which generate negative ions. They claim that ionisers not only clean and refresh the air but also improve the health of people sensitive to excess positive ions. Of course, there are the detractors, other scientists, who dismiss such claims and are skeptical about negative/positive ion research. Therefore people can only make up their own minds by observing the effects on themselves, or on others, of a negative rich or poor environment. After all it is debatable whether depending on seismic readings to anticipate earthquakes is more effective than watching the cat.
1.In accordance with the passage, static electricity can be caused by___.
A.using home-made electrical goods.
B.wearing clothes made of natural materials.
C.walking on artificial floor coverings.
D.copying TV programs on a computer.
2.What effect does exceeding positive ionization have on some people?
A.They think they are insane.
B.They feel rather bad-tempered and short-fussed.
C.They become violently sick.
D.They are too tired to do anything.
3.A high negative ion count is likely to be found___.
A.near a pound with a water pump.
B.close to a slow-flowing river.
C.high in some barren mountains.
D.by a rotating water sprinkler.
4.Some scientists believe that___.
A.watching animals to anticipate earthquakes is more effective than depending on seismography.
B.the unusual behavior of animals cannot be trusted.
C.neither watching nor using seismographs is reliable.
D.earthquake
5.What kind of machine can generate negative ions indoors?
A.Ionisers.
B.Air-conditioners.
C.Exhaust-fans
D.Vacuum pumps.
参考答案:
1.C 2.B 3.D 4.A 5.A
SAT作文素材:progress and sacrifice
SAT写作素材之孔子
SAT写作:避免使用不完整或冗长的句式
SAT作文范文:Risk and Change
SAT作文题目分类:真话假话类
SAT写作6分范文
SAT作文题目分类:个人集体类
SAT写作范例:Is Business Undergraduate Major justified?
SAT作文素材名人类:Audrey Hepburn
SAT作文高分范文之choices in life
SAT作文练习题目 Community Service
SAT写作备考书:KAPLAN和MC-GRAW系列
SAT作文拿高分的三大要素
SAT作文范文:World be better?
SAT写作素材:Frodo in Lord of the Rings
SAT写作范文 含评分标准
SAT作文五段式方法
SAT写作辅导书Barron系列详解
SAT作文题目大全 55-60
SAT作文素材:科学、文学、历史类
SAT写作的几个要点 from CB
SAT作文素材分享(一):Conformity
SAT写作要点:避免口语化和修饰语不当
SAT作文常见论据解析
SAT写作:标点符号的正确用法
SAT作文练习题目3个
SAT作文范例 Catherine Drew Gilpin Faust
SAT写作开头范文两例
如何应对SAT作文词语运用过于简单的问题
SAT写作名人素材艾柯卡
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |