听力原文： Snow is a subject of great interest to weather experts. Experts sometimes have d

ifficulty estimating where, when or how much snow will fall. One reason is that heavy amounts of snow fall in surprisingly small areas. Another reason is that a small change in temperature can mean the difference between snow and rain.

Snow falls in extreme northern and southern areas of the world throughout the year. However, the heaviest snowfalls have been reported in the mountains of other areas during winter. These areas include the Alps in Italy and Switzerland, the coastal mountains of western Canada, and the Sierra Nevada and Rocky Mountains in the United States. In warmer climates, snow is known to fall in areas over four thousand nine hundred meters above sea level.

Snow can be beautiful to look at, but it can also be dangerous.

Snow is responsible for the deaths of hundreds of people in the United States every year. Many people die in traffic accidents on roads that are covered with snow or ice. Others die from being out in the cold or from heart attacks caused by extreme physical activity.

A few years ago, a major storm caused serious problems in the eastern United States. It struck the Southeast in January 1996, before moving up the East Coast. The storm was blamed for more than one hundred deaths. It forced nine states to declare emergency measures.

Virginia and West Virginia were hit hardest. In some areas, snowfall amounts were more than one meter high. Several states limited driving to emergency vehicles. Most major airports were closed for at least a day or two.

A week later, two other storms brought additional snow to the East Coast. In the New York City area, the added weight of the snow forced the tops of some buildings to collapse. Many travelers were forced to walk long distances through deep snow to get to train stations.

People may not be able to avoid living in areas where it snows often. However, they can avoid becoming victims of winter snowstorms.

People should stay in their homes until the storm has passed. While removing large amounts of snow, they should stop and rest often. Difficult physical activity during snow removal can cause a heart attack. It is always a good idea to keep a lot of necessary supplies in the home even before winter begins. These supplies include food, medicine, clean water, and extra power supplies.

Some drivers have become trapped in their vehicles during a snowstorm. If this happens, people should remain in or near their car unless they see some kind of help. They should get out and clear space around the vehicle to prevent the possibility of carbon monoxide gas poisoning.

People should tie a bright-colored object to the top of their car to increase the chance of rescue. Inside the car, they should open a window a little for fresh air and turn on the engine for ten or fifteen minutes every hour for heat.

People living in areas with winter storms should carry emergency supplies in their vehicles. They should include food, emergency medical supplies, and extra clothing to stay warm and dry. People in these areas should always be prepared for winter emergencies.

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