题目内容
（请给出正确答案）
The smog is due ______ invisible gases, mostly from automobile exhaust.
A．from
B．to
C．for
D．with
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New York City has had several London type smog since 1950. Each time there were from 100 to 400 deaths caused by the smog.
In all the killer smog, factories and homes poured smoke and fumes into the air from the furnaces. The chemical fumes combined with the water-droplets in the fog to form. harmful substances. These substances caused the illness of those who breathed the polluted air.
Usually, such harmful fumes rise into the upper air and are blown away by the wind. But sometimes, there is an unusual weather condition called a temperature inversion. A layer of cold air remains near the ground as smoke and fumes pour into it. This is covered by an upper layer of warm air that acts like a lid. It prevents the polluted cooler air rising. The harmful fumes piles up and make people iii. These fumes contain sulfur dioxide, soot particles, and other chemicals. The smog may be so thick that airports are closed and chains of collisions occur on the highways.
Another type of smog occurs in Los Angeles. Here the weather may be clear and sunny, but stinging eyes and dry coughs show that harmful chemicals fill the air. The smog is due to invisible gases, mostly from automobile exhausts. Because these chemicals are changed by the sun up in the air, Los Angeles smog is called Photochemical smog. It contains automobile exhaust fumes and nitrogen oxides changed by the sun' s rays. Added to these are sulfur dioxide and other fumes from factories of oil refineries. Photochemical smog is found in many large cities all over the world.
Killer smog doesn' t happen very often, fortunately. But in many large cities, a combination of automobiles exhaust fumes, home furnace smoke, and factory waste gases pours into the air. This may also happen in the suburbs in the country, where large factories have been built. A number of harmful substances have affected the health of the population.
All of the following together form. smog Except ______ .
A．smoke and fumes
B．snow
C．water drops
D．fog
The Killer Smog
Cases of Killer Smogs
On the night of December 1st, 1930, a dense fog moved over the Meuse Valley, in Belgium. Many factories in the valley poured smoke and fumes into the foggy air. This created dark smog of smoke and fog combined. People in the valley began to cough and strain for breath. The smog remained for four days. During that time, thousands of people became ill. The hospitals were filled with patients. Sixty people died. Most of them were older persons with heart and lung problems. Finally, a heavy rain washed away the smog. Scientists studied the causes of the disaster. They concluded that the illnesses and deaths were caused by chemicals in the smog.
The first reported event of this kind in the United States happened in Donora, a factory town in a valley near Pittsburgh. In 1948, a killer smog made half of the population sick; there were 17 deaths. Again, older people with lung or heart diseases were hit hardest.
London, England, has always been known for its "black fogs". In the winter of 1952, a milky white fog rolled into the city. It soon turned into black smog as the smoke of the city poured into the air. It was so hard to see that people had to walk in front of the buses to guide them. In this way, the most serious air pollution disaster in history began. When it was over, more than 4,000 people had been killed by the thick black smog.
New York City has had several types of smogs since 1950. Each time, there were from 100 to 400 deaths caused by the smog. Although these smogs were not as deadly as London's, New York City has the worst air pollution problem in the United States.
Causes of Killer Smogs
In all the killer smogs, factories and homes poured smoke and fumes into the air from the furnaces. The chemical fumes combined with the water droplets in the fog to form. harmful substances. These substances caused the illness of those who breathed the polluted air.
Usually, such harmful fumes rise into the upper air and are blown away by the wind. But sometimes there is an unusual weather condition called a temperature inversion. A layer of cold air remains near the ground as smoke and fumes pour into it. This is covered by an upper layer of warm air that acts like a lid. It prevents the polluted cooler air from rising. The harmful fumes pile up and make people ill. These fumes contain sulfur dioxide, soot particles, and other chemicals. The smog may be so thick that airports are closed and chains of collisions occur on the highways.
Another type of smog occurs in Los Angeles. Here the weather may be clear and sunny. But stinging eyes and dry coughs show that harmful chemicals fill the air. The smog is due to invisible gases, mostly from automobile exhausts. Because these chemicals are changed by the sun high up in the air, Los Angeles smog is called photochemical smog. It contains automobile exhaust fumes and nitrogen oxides changed by the sun's rays. Added to these are sulfur dioxide and other fumes from factories and oil refineries. Photochemical smog is found in many large cities all over the world.
Harmful Substances Found in Smogs
Killer smogs don't happen very often, fortunately. But in many large cities, a combination of automobile exhaust fumes, home furnace smoke, and factory waste gases pours into the air. This may also happen in the suburbs, or out in the country, where large factories have been built. A number of harmful substances have been found in the air there. When these substances are breathed in day after day, the health of the population is affected.
Sulfur dioxide is formed when fuels containing sulfur are burned. The sulfur combines with the oxygen in the air to form. sulfur dioxide. This gas probably caused most of the deaths in the killer smogs. It combines with the water droplets in the air, o
A．Y
B．N
C．NG
Recent statistics show that, in rich countries at least, many of the worst pollution problems are far smaller than they used to be — and that the costs of this success have so far been small.
Start with air pollution. The dreaded greenhouse gases are still flowing into the atmosphere. But output of gases that attack the ozone layer is well under control. Production of CFCs used in refrigerators has fallen by two-thirds since the mid- 1980s. Many pollutants have been beaten back. The flow of oxides of sulfur, which contribute to evils such as acid rain and smog, has fallen by around a third in rich countries since 1980. Emissions of lead, soot and carbon monoxide—each hazardous to human health—have also fallen sharply.
Water quality has improved in many ways. There is still worry about chemicals, such as fertilizers and heavy metals, draining off the land. But many of the organisms that once infested rich-world waterways — and which still kill millions in poor countries — are retreating steadily. Progress is due largely to the spread of waste water treatment.
Has this cost jobs？ There is no evidence for that. Spending on pollution control amounts to 1% — 2% of GDP in most rich countries, but that has not cut jobs overall.
Question ：What is this passage mainly about？
(30)
A．An arguement for environmental protection.
B．An arguement against environmental protection.
C．An arguement for common citizens.
D．A clarification of a misconception about environment pollution and its cost.
Sulfur dioxide
Sulfur dioxide is produced when coal and oil are burnt or when minerals are "roasted" to remove the sulfur. In some countries, particularly in the northern hemisphere, coal and oil contain significant amounts of sulfur. Unless special steps are taken to remove sulfur dioxide, it is released into the atmosphere. Power stations and industrial plants, which are often sited close to cities, can produce large quantities of the gas.
As well as affecting human health, sulfur dioxide can be harmful to plants, turning leaves yellow and drying, bleaching, and even killing, foliage.
In the atmosphere, sulfur dioxide can form. acidic particles, or react with cloud droplets, contributing to acid rain.
Particles
Particles in the air come from a number of sources, including motor vehicles, industrial processes and wood burning. Secondary formation of particles(formation from gaseous emissions )can also contribute significantly to particle levels. Some atmospheric particles are from natural sources. These include wind-blown dust, pollen, sea salt, and material from volcanic eruptions.
Fine particles(particles with a diameter of 10 micrometres or less)can be inhaled deeply into the lungs and have been associated with a wide range of adverse respiratory symptoms. Long-and short-term exposure to such particles has been linked with increased deaths from heart and lung disease.
Lead compounds, which are emitted by motor vehicles fuelled with leaded petrol, are cumulative poisons. They slowly build up in the body.
Urban haze
Urban haze is mainly due to fine particles, which cause scattering or absorption of light. Haze is typically brown and limits visibility.
Studies by CSIRO scientists have found that there are several types of particles present in haze in Australian cities: organic carbon compounds, elemental carbon or soot, salt, sulfates, nitrates and dust.
Photochemical smog
Sometimes, under certain meteorological conditions, the combined effects of a number of air pollutants are worse than the individual effects. Photochemical smog, sometimes seen as a whitish haze present over cities during summer, is an example of this. Photochemical smog is formed on still days when the sun shines on air containing volatile organic compounds(VOCs)and oxides of nitrogen. Volatile organic compounds include hydrocarbons, as well as alcohols, aldehydes and ethers. VOCs in the air arise mainly from automotive fuels and industrial solvents. Chemical reactions driven by sunlight and involving VOCs and oxides of nitrogen form. ozone, a gas harmful to humans, animals and plants.
Air quality indoors
Australians on average spend about ninety-five percent of their time indoors and many pollutants occur at higher concentrations indoors than outdoors because of the materials and appliances used in buildings.
Many people's main exposure to air pollutants occurs when they are indoors, such as at home, in the workplace or in entertainment venues.
Researchers are working towards measuring individual exposure to pollutants. That is, a measure of the actual exposure that people have to air pollutants during their daily routines, rather than measures of pollution at fixed locations.
CSIRO regularly uses personal air pollution detectors, which monitor concentrations of pollutants that people breathe. The inexpensive samplers offer scientists, environmentalists, engineers and others a simple but accurate way of measuring selected pollutants in air. The sampler, based on a Swedish
design, is small and requires no electricity so is ideal for remote use. Nitrogen dioxide, sulfur dioxide, ammonia and oth
A．Y
B．N
C．NG
Smog has become the most serious type of pollution.
A．Y
B．N
C．NG
The smog spread to neighbouring countries.
A．Right
B．Wrong
C．Not mentioned
The smog spread to neighbouring countries．
A．Right
B．Wrong
C．Not mentioned
The word "smog" first appeared in 1952.
A．Right
B．Wrong
C． Not mentioned
Photochemical smog is formed on rainy days when chemicals are combined with smoke.
A．Y
B．N
C．NG
