A weather map is an important tool for geographers. A succession of three of four maps presents a continuous picture of weather changes. Weather forecasts are able to determine the speed of air masses and fronts; to determine whether an individual pressure area is deepening or becoming shallow and whether a front is increasing or decreasing in intensity. They are also able to determine whether an air mass is retaining its original characteristics or taking on those of the surface over which it is moving. Thus, a most significant function of the map is to reveal a synoptic picture of conditions in the atmosphere at a given time.
All students of geography should be able to interpret a weather map accurately. Weather maps contain an enormous amount of information about weather conditions existing at the time of observation over a large geographical area. They reveal in a few minutes what otherwise would take hours to describe. The United States weather Bureau issues information about approaching storms, floods, frosts, droughts, and all climatic conditions in general. Twice a month it issues a 30-day outlook which is a rough guide to weather conditions likely to occur over broad areas of the United States. These 30-day outlooks are based upon an analysis of the upper air levels with often set the stage for the development of air masses, fronts, and storms. Considerable effort is being exerted today to achieve more accurate weather predictions. With the use of electronic instruments and earth satellites, enormous gains have taken place recently in identifying and tracking storms over regions which have but few meteorological stations. Extensive experiments are also in progress for weather modification studies. But the limitations of weather modification have prevented meteorological results except in the seeding of super-cooled, upslope mountainous winds which have produced additional orographical precipitation on the windward side of mountain ranges. Nevertheless, they have provided a clearer understanding of the fundamentals of weather elements.
1 One characteristic of weather maps not mentioned by the author in this passage is .
A wind speed
B thermal changes
C fronts
D barometric pressure
2 The thirty-day forecast is determined by examining .
A upper air levels
B satellite reports
C changing fronts
D daily air maps
3 The observation of weather conditions by satellites is advantageous because it .
A gives the scientist information not obtained readily otherwise
B enables man to alter the weather
C uses electronic instruments
D is modern
4 A weather map is synoptic because it .
A summarizes a great deal of information
B can be interpreted accurately
C appears daily
D shows changing fronts
5 At the present time, experiments are being conducted in .
A 30-day outlook
B controlling storms
C satellites
D manipulating weather
参考答案
1. B2. A3. D4. A5. D
雅思听力技巧:把握五大技巧
雅思听力好习惯具体要如何培养
雅思听力技巧:观点题如何拿高分
雅思听力考试的冷门知识点易得分
雅思听力考试的六个小贴士
雅思听力提升关键:文化背景知识
语言学家教你提高雅思听力
雅思听力和雅思阅读的通用技巧:把握主题
VOA慢速英语练习雅思听力的三个步骤
雅思听力 常出现的英美地名盘点
雅思听力如何提高?听抄训练最有效
揭秘雅思听力是如何出题的
快速提高雅思听力水平的三个方法
雅思听力备考的五个要点
雅思听力和雅思口语的备考方法
雅思听力考试的最终目的是什么?
运用双向听力法优化雅思听力练习
雅思听力技巧:怎样读题
雅思听力难度增加 立体训练法沉着应对
雅思听力场景解析:相貌篇
雅思听力水平与口语能力可以共同提高
雅思冷门听力 动物学场景考察特点
雅思听力备考中的矛盾问题:痛苦与成就感
雅思听力训练中的4个具体问题
雅思听力练习的好材料:BBC
从VOA慢速英语入手突破雅思听力
剑桥雅思听力资料的使用技巧
雅思听力词汇之图书馆词汇
细说提高雅思听力水平的方法
雅思听力必备20短语
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |