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.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.
2.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.
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.What kind of machine can generate negative ions indoors?
A.Ionisers.
B.Air-conditioners.
C.Exhaust-fans
D.Vacuum pumps.
5.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
答案:BCDAA
体坛英语资讯:Richarlyson weeps in farewell
体坛英语资讯:Corinthians draw 1-1 against Goias
国内英语资讯:China, Uruguay vow to expand trade, investment cooperation
我们应该学会尊重差异
体坛英语资讯:Fluminense wins Brazilian Championship after 26 years
体坛英语资讯:Real Madrid qualify for knockout stage after drawing 2-2 with AC Milan
体坛英语资讯:Serbia wins Davis Cup
国内英语资讯:China to commemorate 80th anniversary of Long March victory
国际英语资讯:AIIB holds first intl advisory panel meeting
史上最大的泡沫 中国楼市暴涨引崩盘担忧
体坛英语资讯:Real Madrids Canales out for rest of 2010
国内英语资讯:Chinese leaders watch gala marking 80th anniversary of Long March victory
国内英语资讯:Spotlight: BRICS summit boosts confidence in global economic growth
中西饮食差异
体坛英语资讯:Ancelotti focusing on attack to shift Bayerns fortunes
塔利班正式否认与阿富汗政府会晤的相关报道
国际英语资讯:Spotlight: Iraqs operation to liberate Mosul receives international support amid humanitari
体坛英语资讯:Palmeiras makes offer to Roma for Adriano
体坛英语资讯:Real Madrid to use squad players against Auxerre
体坛英语资讯:Corinthians star midfielder Elias in scopes of Benfica
体坛英语资讯:Deportivo beat Hercules 1-0 in dull encounter
国内英语资讯:China comments on Japans withholding dues to UNESCO
体坛英语资讯:Schalke sweeps St. Pauli 3-0 at German Bundesliga
体坛英语资讯:Barca beat Ruben Kazan 2-0 in Champions League
体坛英语资讯:England pull out of 2022 World Cup bidding
体坛英语资讯:Geoff Ogilvy wins Australian Open in Sydney
体坛英语资讯:France takes dramatic lead over Serbia in Davis Cup final
体坛英语资讯:Flamengos Bruno receives first sentence of 4.5 years in jail
体坛英语资讯:FIFA not thinking about changes to 2022 World Cup in Qatar
体坛英语资讯:Nadal stages overwhelming debut show at Shanghai Masters
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |