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.
答案:1.C 2.B 3.D 4.A 5.A
中朝“互市贸易区”落户辽宁
北京电网“最大负荷”破纪录
4种情境 英美国人的不同表现
中国央行救市是中国版量化宽松
女子为登脸书改名换姓
中国上半年进出口总值下降
日本军工企业谨慎扩张市场 首选东南亚及印度
单身狗怨谁 都是基因惹的祸
埃博拉疫苗气雾剂成功通过动物实验
屏幕阅读pk纸质阅读
周杰伦当爹喜得千金
上不了网或手机无信号,人就会焦虑不安
苹果用户对视网膜屏幕问题表示不满
中国作为制造业投资首选地的魅力下降
华为收购Amartus电信网络管理业务
世界首富也有遗憾 盖茨后悔没学二外
希腊议会将为新改革方案投票
探测器“飞掠”冥王星
匈牙利筑围墙阻挡移民
美国网络防御战效率堪忧
年度全球最丑狗:“钟楼怪人”丑出新高度
双语囧研究 爱抠鼻屎说明你懒惰
美国后院的债务危机
四成人不在意手机能否接电话
新iPhone将会有哪些改变?
惊险!雄狮公路猎杀羚羊 距游客仅1米
一只脚跨过“鬼门关”:希腊不会退出欧元区
英国监管部门放弃伦敦鲸调查
《生活大爆炸》过审 第八季7月国内复播!
小七4岁啦!帅爸贝克汉姆晒女儿庆生照
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |