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
高效记忆托福单词:词根"form"同源词汇解析
【托福词根的联想】Word List 4
托福词汇记忆方法优缺点介绍
【托福词根联想】Word List 2
【托福词根的联想】Word List 2
托福词汇:"And"特殊用法及汉译
托福阅读词汇选集(4):CD
托福考试——词汇学习建议
【托福词根联想】Word List 1
托福阅读词汇选集(1):A
【托福词根联想】Word List 1
托福听力背景词汇:预约医生
托福阅读词汇选集(2):ABC
【托福词根的联想】Word List 4
托福词汇记忆两大误区解决办法
【托福词根联想】Word List 1
【托福词根联想】Word List 2
托福备考误区:学习托福就是背单词
托福听力背景词汇:预约医生
【托福词根的联想】Word List 4
托福写作词汇活用 向高分突进
【托福词根联想】Word List 2
【托福词根的联想】Word List 2
【托福词根的联想】Word List 5
【托福词根联想】Word List 2
托福阅读词汇选集(3):C
托福阅读词汇选集(5):DE
【托福词根联想】Word List 1
【托福词根联想】Word List 1
新托福考试词汇该如何备考 分类别记忆最有效
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |