VOA慢速英语2014 Lots of Snow Covers Much of the United States This Winter 这个冬天大雪覆盖美国大部分地区（在线收听）

Lots of Snow Covers Much of the United States This Winter 这个冬天大雪覆盖美国大部分地区

From VOA Learning English, this is Science in the News.  I’m Caty Weaver.

这里是来自美国之音英语学习的科学动态栏目. 我是凯迪-韦弗.

And I’m Mario Ritter.  Today, we will tell you about snow.  People in many parts of the United States have had the chance to learn a lot about snow this winter.  Snow fell in almost every state. 

我是马里奥-里特. 今天我们将要讨论雪. 这个冬天在美国很多地方的人们有机会接触到雪. 差不多每一个州有降雪.

Large amounts of snow fell on the northeastern states of New York and New Jersey in January and early February.  Millions of Americans live in, or travel through, these states.  The Northeast is home to many major airports.  The bad weather forced officials to cancel thousands of flight.

在一月和二月初,纽约东北方向的州和新泽西州下了大量的雪. 成千上万的美国人住在那里, 或者出差, 旅行到这些大雪覆盖的州. 东北区域是很多大型机场的基地所在. 糟糕的天气迫使管理层取消了数千个航班.

Earlier, in December, there were several big rain and snow storms.  At one point, snow fell on almost every part of the country and in almost every state.  The National Oceanic and Atmospheric Administration said it was the eighth largest December snow cover on record, and the largest since December of 2009.

在十二月的早期, 下了几场大雨, 刮了几场暴风雪. 一段时间以来, 国家的每个地方和每个州, 几乎都有降雪. 美国国家海洋气象局说这次是有记录以来十二月积雪覆盖第八个最高的, 也是自2009年12月份以来最大的一场.

Weather experts say snow may continue to fall in many areas through March. 

气象预报说三月份会有很多地方持续下雪.

Snow is a subject of great interest to weather experts.  It is difficult to predict 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. 

对气象预报员来说下雪是一个很好聊的主题. 在哪里, 什么时候下或者下多少是很难预测的. 其中一个原因是在一个小地区会下很多雪. 另外一个原因是下雪和下雨的温度区别很小.

Just what is snow, anyway?  Snow is a form of frozen water.  It contains groups of ice particles called snow crystals.  These crystals grow from water droplets in cold clouds.  They usually grow around dust particles. 

什么是雪呢? 雪是水结冰的一种形式. 它是一种叫做雪晶的冰物质集合. 这种晶体是生长于冷云中的水滴. 它们发展在灰尘物质的周围.

All snow crystals have six sides, but they grow in different shapes.  The shape depends mainly on the temperature and water levels in the air.

所有的雪晶有六面, 但他们的形状不同. 形状主要依赖于空气中的温度和水位.

Snow crystals grow in one of two designs: plate-like and columnar.  Plate-like crystals are flat.  They form when the air temperature is about 15 degrees below zero Celsius.  Columnar snow crystals look like little sticks of ice.  They form when the temperature is about five degrees below zero.

雪晶有两种形状: 板状和柱状. 板状晶体是平的. 他们形成于零下15摄氏度到0度的温度中. 柱状晶体看起来像小冰柱. 他们形成于零下5度到0度.

The shape of a snow crystal may change from one form to another as the crystal passes through levels of air with different temperatures.  When melting snow-crystals or raindrops fall through very cold air, they freeze to form small particles of ice, called sleet.  Groups of frozen water-droplets are called snow pellets.  Under some conditions, these particles may grow larger and form solid pieces of ice, or hail.  Hail can be dangerous to people, animals and property.

雪晶的形状会从一个形状变换成另外一个形状就像晶体在不同温度空气中的变化水平. 当正在融化的雪晶或者雨滴进入冷空气中, 他们紧紧抓住冰的小颗粒, 这被称作雨夹雪. 成群的冻结水滴被称为雪丸. 在一些情况下, 这些物质可以变大并且构成冰固体物质, 或者冰雹. 冰雹对于人类, 动物和财产来说是危险的.

When snow crystals stick together, they produce snowflakes.  Snowflakes come in different sizes.  As many as 100 crystals may join to form a snowflake larger than two and one-half centimeters.  Under some conditions, snowflakes can form that are five centimeters across.  Usually, this requires near-freezing temperatures, light winds and changing conditions in Earth’s atmosphere. 

当雪晶粘在一起的时候, 他们形成了雪花. 雪花有不同的尺寸. 大概100个晶体结合到一起形成的雪花的尺寸大于2.5厘米. 在一些情况下, 雪花的直径可以形成至5厘米. 这通常要求大气中的温度接近于零度, 有微风和条件变化.

Snow contains much less water than rain.  About two and one-half centimeters of rain has as much water as 15 centimeters of wet snow.  About 76 centimeters of dry snow equals the water in two and one-half centimeters of rain.

跟雨比起来, 雪包含的水要少很多. 2.5厘米的雨水所包含的水量相当于15厘米湿雪的水量. 76厘米的干雪所包含的水量相当于2.5厘米雨水的水量.

Much of the water the world uses comes from snow.  Melting snow provides water for rivers, power stations and crops.  Mountain snow provides up to 75 percent of all surface water supplies in the western United States. 

世界范围内用很多水来自于雪. 融化的雪提供水给河流, 发电站和农作物. 山脉上的雪给美国西部境内75%自来水公司提供了水.

Snowfall helps to protect plants and some wild animals from winter weather.  Fresh snow is made largely of air trapped among the snow crystals.  Because the air has trouble moving, the movement of heat is limited. 

在冬天, 降雪有助于保护植物和一些野生动物. 初雪主要是由在雪晶间的空气阀构成.因为空气的流通, 热运动受到限制.

Snow can also influence the movement of sound waves.  When there is fresh snow on the ground, the surface of the snow absorbs, or takes in, sound waves.  However, snow can become hard and flat as it grows older or if there have been strong winds.  Then, the snow’s surface will help to send back sound waves.  Under these conditions, sounds may seem clearer and may travel farther.

雪还可以影响声波的运动. 处于地面的初雪, 它的表面能吸收, 或收纳声波. 不管怎样, 当它存在的时间变长, 或者有大风, 雪能够变硬, 变平. 然后, 雪的表面能帮助反射声波. 在这些情况下, 声音变得清晰, 可能会传的更远.

Generally, snow and ice appear white.  This is because the light we see from the sun is white.  Most natural materials take in some sunlight.  This gives them their color.  However, when light travels from air to snow, some light is sent back, or reflected.  Snow crystals have many surfaces to reflect sunlight.  Yet the snow does take in a little sunlight.  It is this light that gives snow its white appearance. 

一般来说, 雪和冰表现为白色. 因为我们看到来自太阳的光是白色的. 大部分自然的物质吸收一些太阳光, 以表现为他们的颜色. 无论如何, 当太阳穿过云层到雪表面, 一些光反射, 一些光折射. 雪晶有很多面能折射太阳光. 雪吸收一点太阳光. 这些光能够让雪呈现出白色.

Snow or ice may sometimes appear to be blue.  The blue light is the product of a long path through the snow or ice.  Think of snow or ice as a filter.  A filter is designed to reject some substances, while permitting others to pass through.  In the case of snow, light makes it through if the snow is only a centimeter thick.  If it is a meter or more thick, however, blue light often can be seen.

雪或冰有时表现为蓝色. 蓝光是一长段雪或冰的产物. 把雪或冰想成一个过滤器. 过滤器的设计就是为了过滤掉一些物质同时允许其他的物质通过. 至于雪, 如果雪只有一厘米厚, 则光能够穿透.如果雪有一米或者更厚, 则能看到蓝光.

Snow falls in the Earth’s extreme North and South 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.  Snow is even known to fall near the Equator -- but only on the highest mountains. 

这一年从南极到北极都有雪. 然而, 有报道说在冬季, 最严重的降雪是在其他地区的山区. 这些地区包括意大利和瑞士的阿尔卑斯山, 加拿大西部沿海山脉, 和美国境内的内华达山脉和落基山脉. 在赤道附近都有雪的痕迹 – 但也只是在最高的山峰上.

The continental United States has an average of 105 snowstorms each year.  An average storm produces snow for between two and five days. 

美国大陆平均每年有105次暴风雪. 平均每次暴风雪产生雪要2到5天.

Almost every part of the U.S.  has received snowfall at one time or another.  Even parts of southern Florida have reported a few snowflakes.

几乎美国的每个地方曾经都有下过雪. 甚至佛罗里达南部的每个地方都报道过有雪.

Many countries have little or no natural snowfall, but people who live in those areas still want to see snow.  So scientists have come up with a solution.  In 1936, a physicist from Japan produced the first man-made snow in a laboratory.  Then, during the 1940s, American scientists developed methods for making snow in other areas.  Clouds with extremely cool water are mixed with man-made ice crystals, such as silver iodide and metaldehyde crystals.  Sometimes, dry ice particles or liquid propane are used.  Today, machines are used to produce limited amounts of snow for ski areas when not enough natural snow has fallen.

很多国家的自然降雪很少, 甚至是没有. 但住在这些国家的人们很想看到雪. 所以科学家正加紧找解决方案. 在1936年, 来自日本的物理学家在实验室制造了第一场人工降雪. 然后在1940年代, 美国科学家在其他地区发展了人工造雪的方法. 带有极度寒冷的水的云与人造冰晶, 比如: 碘化银和聚乙醛晶体, 混合在一起. 有时用干冰粒或液态四聚乙醛晶体. 今天, 在滑雪地区, 当没有足够的自然雪时, 机器用于生产有限数量的雪.

Snow may be beautiful, but it can be deadly.  It 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 too much physical activity. 

雪可能是美丽的, 但它能是致命的. 每一年在美国, 数百人因雪丧生. 很多人丧命于被雪和冰覆盖的路面. 其他人因为寒冷丧命, 或者太多身体活动造成心脏病发作.

You may not be able to avoid living in areas where it snows often.  However, you can avoid becoming a victim of a snowstorm.  Most people are told to stay in their homes until the storm has passed.  When removing large amounts of snow, they should stop and rest often.  Difficult physical activity during snow removal can cause a heart attack, especially among older adults. 

你可能不能避免生活在经常下雪的地区. 然而, 你可以避免成为暴风雪的受害者. 大多数人被告知在暴风雪结束前, 呆在自己的家里. 当移除大量的雪的时候, 人们需要停下并休息. 在清除雪的过程中, 人们行动的不便造成心脏病发作, 这种病常发于老年人中.

It is always a good idea to keep a lot of supplies in the home, even before winter begins.  These supplies include food, medicine, clean water and extra power supplies. 

在家里存有大量的库存一直是一个不错的注意, 甚至打从冬天开始. 这些库存包括食物, 药物, 干净的水和额外的备用电源.

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’s exhaust pipe.  This will lower the chance that poisonous carbon monoxide gas enters the car. 

在暴风雪中一些司机围困在汽车中. 如果有人碰到这种情况发生, 不能寻求到帮助, 应当呆在车里或者在车的附近. 被围困的人们应当到车外清理围在汽车排气管周围的雪. 这样可以降低有毒的一氧化碳气体进入车内.

Drivers 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. 

司机应在车顶绑一个颜色鲜艳的物体以增加营救的机会.在车内, 司机需要打开一点窗户让新鲜空气进来, 并且每小时内打开十到十五分钟的引擎用于加热.

People living in areas where winter storms are likely should carry emergency supplies in their vehicle.  These include food, emergency medical supplies and extra clothing to stay warm and dry.  People in these areas should always be prepared for winter emergencies.  Snow can be beautiful, but it can also be dangerous. 

住在冬季有暴风雪地区的人们或许应该备一些应急物资在车里. 这些应急物资包括食物, 应急医疗用品和额外的衣服以保证温暖和干燥.

This Science in the News was written by Christopher Cruise.  Our producer was June Simms.  I’m Mario Ritter.

这篇科技报道是由克里斯托弗-克鲁斯所写.制作人是琼-西姆斯. 我是马里奥-里特.