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. Snow is even known to fall near the Equator (赤道)，but only on the highest mountains.
Snow contains much less water than rain, but much of the water the world uses comes from snow. Melting snow provides water for rivers, electric power stations and agricultural crops. In the western United States, mountain snow provides up to seventy-five percent of all surface water supplies.
Snowfall helps to protect plants and some wild animals from winter weather. Fresh snow is made largely of air trapped among the snow crystals (晶体). Because the air has trouble moving, the movement of heat is limited. Snow also influences the movement of sound waves. The surface of the snow takes in, or absorbs, sound waves. As snow grows older or if there have been strong winds, it can become hard and flat. Then, the snow，s surface will help to send back sound waves.
Snow may be beautiful, but it can be deadly. It is responsible for the deaths of hundreds of people. Many people die in traffic accidents on roads covered with snow and ice or from being seriously stuck in the winter storm. Others die from heart attacks caused by too much physical activity out in the cold.
People may not be able to avoid living in areas where it snows often. However, they can avoid becoming victims of snowstorms. People should stop driving and stay at home until the storm has passed. People living in these areas should carry emergency supplies in their vehicle. These include food，emergency medical supplies，and extra clothing to stay warm and dry.
小题1:Mountain snowfall _____.
A．is heavier than that in the South and the North Poles
B．has never occurred near the Equator of the earth
C．brings less of the water the world uses than rain does
D．provides up to seventy—five percent of water supplies worldwide小题2:Snow protects plants and wild animals from cold weather by _____.
A．supplying much more air
B．limiting heat movement
C．absorbing strong winds
D．sending back sound waves小题3:Snow can be deadly mainly because it can _____.
A．cause road accidents
B．make people stuck in winter storms
C．lead to heart attacks
D．make people victims of snowstorms小题4:What will the text probably tell us following the last paragraph? _.
A．How to drive during snowstorms
B．Where we can get emergency supplies
C．How to prevent heart attacks out in cold
D．Why we should stay warm and dry in winter
小题1:A
小题2:B
小题3:D
小题4:C
题目分析：文章讲述了雪的作用，能帮助动植物过冬，是主要的水的来源，及讲到了如何来避免在暴风雪中成为受害者。
小题1:细节题。文章第一自然段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.可知，南极或北极终年积雪，但是，最大的雪却经常发生在山区。可知，山区的雪量比南北极的大。
小题2:细节题。从第三自然段Because the air has trouble moving, the movement of heat is limited.可知雪能够保护动植物过冬，是因为它能够阻止热的散失。故选B。
小题3:细节题。从第二自然段及第三自然段People may not be able to avoid living in areas where it snows often. However, they can avoid becoming victims of snowstorms.可知，A,B,C选项只是某一方面，并不全面，D选项回答更为全面。使人们成为了暴风雪的受害者。
小题4:细节推断题。从文章最后一句话可知，人们应该常备一些急救的药物或温暖的衣服，所以接下来应该是讲在冬天的户外如何来防止心脏病的发生。故选C。
点评：本文文脉清晰，对雪的自然现象、雪的作用及如何避免受伤三方面进行了说明。把握好这条主线，文章细节题居多，题目设置也不难，只需仔细的将问题和文章进行对比即可得出正确的答案。
