新视野大学英语视听说教程 4 Unit 3-4

（单词翻译）

Task3: A Blizzard¹
Script
A blizzard is a sever² weather condition characterized by low temperatures and strong winds, greater than 15 miles per hour, bearing a great amount of snow.
Because the factors for classifying winter storms are complex, there are many different definitions of what a blizzard truly is. But it is generally agreed that in order to be classified as a blizzard, as opposed to merely a winter storm, the weather must meet several conditions. The storm must decrease visibility to a quarter of a mile for three hours running. Include snow or ice as precipitation, and have wind speed of at least 32 miles per hour, which means Force 7 or more on the Wind Scale.
Another standard, according to Environment Canada, is that the winter storm must have winds of 40 kilometers per hour or mi=ore, plenty of snow, visibility less than 1 kilometer, a temperature of less than -25 degrees Celsius³, and all of these conditions must last for 4 hours or more, before the storm can properly be called a blizzard.
When all these conditions continue after snow has stopped falling, the storm is referred t o as a ground blizzard.
An extensive form of blizzard is a whiteout, when the downdrafts, together with snowfall, become so sever that it is impossible to distinguish the ground from the air. People caught in a whiteout can quickly become disoriented, losing their sense of up and down as well as their sense of direction. Severe blizzard can also occur along with arctic cyclones⁴.

1. What is the passage mainly about?
2. Which of the following is true of a blizzard according to the first standard?
3. Which of the following is true of a blizzard according to the second standard?
4. What is a ground blizzard?
5.  Which of the following is in the order of increasing force?

Keys: 1A 2.B3. C 4.D 5.C

For Reference
They can quickly become disoriented, losing their sense of up and down as well as their sense of direction.