A weather map is an important tool for geographers. A succession of three or four maps pre

A weather map is an important tool for geographers. A succession of three or four maps presents continuous picture of weather changes. Weather forecasters are able to determine the speed of air masses and fronts (气锋) to determine whether an individual pressure aroa is deepening or becoming shallow and whether a front is increasing or decreasing in intensity (强烈).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 summary 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 and all climatic conditions in general. Twice a month it issues a 30-dayoutlook 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 anaiysis of the upper air levels which often set the stage for development of air masses, fronts and storms.
Considerable effort is being exerted today to achieve more accurate weather
predictions, with identifying and tracking storms over regions which have but few meteorological (气象)stations. Extensive experiments are also in progress for weathef modification studies.
【小题1】 One characteristic of weather maps NOT mentioned by the author in this passage is .A．floodsB．frontsC．temperature changesD．frosts【小题2】 The thirty-day forecast is determined by examining .A．daily weather mapsB．upper air levelsC．satellite reportsD．changing fronts【小题3】The observation of weather conditions by satellites is helpful because it A．is modernB．uses electronic instrumentsC．makes weather prediction easierD．shows things that would otherwise take hours to describe in a few minutes【小题4】A weather map is a summary because it A．sums up a great deal of informationB．appears dailyC．shows changing frontsD．is a science book【小题5】You may possibly read this article in .A．a magazineB．newspaperC．a novelD．a science bookC

(答案→)C 解析：【小题1】从第一、二段可以发现fronts, floods, frost都被提到。没有提到C【小题1】细节题：从第二段的句子：These 30-day outlooks are based upon an anaiysis of the upper air levels which often set the stage for development of air masses, fronts and storms.可知30天的天气预报是基于上层空气水平的。选B【小题1】细节题：从第二段的句子：They reveal in a few minutes what otherwise would take hours to describe.可知通过气象卫星观察天气条件是有帮助的，因为它在几分钟内展示的是要花几个小时才能展示的东西。选D【小题1】细节题:从第一段的最后一句话：a most significant function of the map is to reveal a summary picture of conditions in the atmosphere at a given time. 可知气象地图很重要，因为它总结了大量信息。选A【小题1】文章出处题：文章讲的是通过天气地图了解相关的天气信息。属于科学类短文。选D

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